Robert Burns and Catherine Lucey, The Associated Press 

 



WASHINGTON -- U.S. Defence Secretary Jim Mattis on Sunday shot back at North Korea's latest nuclear provocation with a blunt threat, saying the U.S. will answer any North Korean threat with a "massive military response -- a response both effective and overwhelming." While he said America does not seek the "total annihilation" of the North, he added somberly, "We have many options to do so."

In a brief statement to reporters outside the White House, Mattis said the international community is unified in demanding the denuclearization of the Korean peninsula and said the North's leader, Kim Jong Un, should know that Washington's commitment to Japan and South Korea is unshakeable.

Earlier, President Donald Trump raised the stakes in the escalating crisis over North Korea's nuclear threats, suggesting drastic economic measures against China and criticizing ally South Korea.

With Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, at his side, Mattis said, "Any threat to the United States or its territories, including Guam, or our allies will be met with a massive military response -- a response both effective and overwhelming." Those words alone were within the usual bounds of U.S. commentary on answering North Korean aggression. But he seemed to take it a step further with the reference to "total annihilation."

Mattis, who did not take questions from reporters, said he had attended a "small group" national security meeting with Trump and others. He said the president wanted to be briefed on each of what Mattis called "many military options" for action against North Korea. He did not mention any specific options, but his comment suggested that they discussed everything from a show of force such as an overflight of the peninsula by U.S. bombers to the latest war plan for destroying the North's weaponry and eliminating its leadership.

"We made clear that we have the ability to defend ourselves and our allies, South Korea and Japan, from any attacks, and our commitments among the allies are ironclad," he said. The use of Mattis as the president's spokesman in this circumstance was, by itself, a reflection of the growing risk that the crisis could escalate to military action.

"Kim Jong Un should take heed of the United Nations Security Council's unified voice - all members unanimously agreed on the threat North Korea poses, and remain unanimous in their commitment to the denuclearization of the Korean peninsula - because we are not looking to the total annihilation of a country - namely, North Korea," Mattis said, reading from a piece of paper. "But, as I said, we have many options to do so."

North Korea claimed "perfect success" in an underground test of what it called a hydrogen bomb -- potentially vastly more destructive than an atomic bomb. It was the North's sixth nuclear test since 2006, but the first since Trump took office in January.

Trump, asked by a reporter during a trip to church services if he would attack the North, said: "We'll see."

No U.S. military action appeared imminent, and the immediate focus appeared to be on ratcheting up economic penalties, which have had little effect thus far. Members of Congress expressed alarm at the North's test and emphasized strengthening U.S. missile defences. Leaders in Russia, China and Europe issued condemnations.

Trump said he was meeting at the White House with chief of staff John Kelly, Mattis "and other military leaders." Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, also attended, according to his spokesman.

The precise strength of the underground nuclear explosion had yet to be determined. South Korea's weather agency said the artificial earthquake caused by the explosion was five times to six times stronger than tremors generated by the North's previous five tests.

North Korea's state-run television broadcast a special bulletin to announce the test, and said Kim attended a meeting of the ruling party's presidium and signed the go-ahead order. Earlier, the party's newspaper published photos of Kim examining what it said was a nuclear warhead being fitted onto an intercontinental ballistic missile.

Sunday's detonation builds on recent North Korean advances that include test launches in July of two ICBMs that are believed to be capable of reaching the mainland U.S. The North says its missile development is part of a defensive effort to build a viable nuclear deterrent that can target U.S. cities.

The Arms Control Association said the explosion appeared to produce a yield in excess of 100 kilotons of TNT equivalent, which it said strongly suggests the North tested a high-yield but compact nuclear weapon that could be launched on a missile of intermediate or intercontinental range.

Hans Kristensen, a nuclear weapons expert at the Federation of American Scientists, said the North probably will need to do more tests before achieving a functioning hydrogen bomb design.

Beyond the science of the blast, North Korea's accelerating push to field a nuclear weapon that can target all of the United States is creating political complications for the U.S. as it seeks to balance resolve with reassurance to allies that Washington will uphold its decadeslong commitment to deter nuclear attack on South Korea and Japan.

That is why some questioned Trump's jab Sunday at South Korea. He tweeted that Seoul is finding that its "talk of appeasement" will not work. The North Koreans, he added, "only understand one thing," implying military force might be required. The U.S. has about 28,000 troops stationed in South Korea and is obliged by treaty to defend it in the event of war.

Patrick Cronin, an Asia expert with the Center for a New American Security, said Trump's comment on South Korea was probably "intended to stiffen the spine of an ally." He said he agreed with the intention.

"I think Washington is very serious about showing some unexpected resolve," he said. "We need our ally and we need to remain ironclad. But at the same time, we can't afford South Korea to go weak in facing down this growing danger."

Trump also suggested putting more pressure on China, the North's patron for many decades and a vital U.S. trading partner, in hopes of persuading Beijing to exert more effective leverage on its neighbour. Trump tweeted that the U.S. is considering "stopping all trade with any country doing business with North Korea." Such a halt would be radical. The U.S. imports about $40 billion in goods a month from China, North Korea's main commercial partner.

Secretary of State Rex Tillerson was calling counterparts in Asia, and Trump's treasury secretary, Steven Mnuchin, said he was putting together proposed new sanctions for Trump to consider that would seek to cut off trade with North Korea.

It's unclear what kind of penalties might make a difference. Lassina Zerbo, head of the U.N. test ban treaty organization, said sanctions already imposed against North Korea aren't working.

China's official Xinhua News Agency said President Xi Jinping and Russian leader Vladimir Putin, meeting on the sidelines of a Beijing-led economic summit, agreed "to adhere to the goal of the denuclearization of the Korean Peninsula, have close communication and co-ordination and properly respond" to the test.

Experts have questioned whether the North has gone too far down the nuclear road to continue pushing for a denuclearization of the Korean Peninsula, an Obama administration policy goal still embraced by Trump's White House.

"Denuclearization is not a viable U.S. policy goal," said Richard Fontaine, president of the Center for a New American Security, but neither should the U.S. accept North Korea as a nuclear power. "We should keep denuclearization as a long-term aspiration, but recognize privately that it's unachievable anytime soon."

Trump warned last month that the U.S. military was "locked and loaded, should North Korea act unwisely" and that the U.S. would unleash "fire and fury" on the North if it continued to threaten America. The bellicose words followed threats from North Korea to launch ballistic missiles toward the U.S. Pacific territory of Guam, intending to create "enveloping fire" near the military hub that's home to U.S. bombers and other aircraft.

Associated Press writers Eric Talmadge in Tokyo contributed to this report.</s>An earthquake measuring 5.6 on the Richter scale was detected around North Korea’s nuclear test site on Sunday, the Seoul military said indicating that Pyongyang has conducted its sixth nuclear test.

The artificial quake wave was detected around the Punggye-ri site in the North Hamgyeong province, according to the Joint Chiefs of Staff.

The military said it was analysing whether the temblor came from a nuke test, reports Yonhap News Agency.

Seoul’s weather agency said that the seismic wave was recorded at 12.36 p.m.

The USGS said the epicentre was recorded 24 km east-northeast of Sungjibaegam and zero km deep.

South Korean President Moon Jae-in has convened an emergency National Security Council (NSC) meeting following the earthquake and a report by North Korean state-media that Kim Jong-un inspected a hydrogen bomb being loaded into a new intercontinental ballistic missile (ICBM) after it claimed to have made a “more developed nuke”.

Since 2006, North Korea has carried out five nuclear tests, including two last year.</s>SEOUL, Korea, Republic Of — Following U.S. warnings to North Korea of a “massive military response,” South Korea fired missiles into the sea to simulate an attack on the North’s main nuclear test site on Monday, a day after North Korea detonated its largest-ever nuclear test explosion.

South Korea’s Defence Ministry also said Monday that North Korea appeared to be planning a future missile launch, possibly of an ICBM, to show off its claimed ability to target the United States with nuclear weapons, though it was unclear when this might happen.

The heated words from the United States and the military manoeuvrs in South Korea are becoming familiar responses to North Korea’s rapid, as-yet unchecked pursuit of a viable arsenal of nuclear-tipped missiles that can strike the United States. The most recent, and perhaps most dramatic, advance came Sunday in an underground test of what leader Kim Jong Un’s government claimed was a hydrogen bomb, the North’s sixth nuclear test since 2006.

The United Nations Security Council planned to hold its second emergency meeting about North Korea in a week on Monday to discuss responses to the test.

In Seoul, Chang Kyung-soo, an official with South Korea’s Defence Ministry, told lawmakers on Monday that it was seeing preparations in the North for an ICBM test but didn’t provide details about how officials had reached that assessment. Chang also said the yield from the latest nuclear detonation appeared to be about 50 kilotons, which would mark a “significant increase” from North Korea’s past nuclear tests.

In a series of tweets, U.S. President Donald Trump threatened to halt all trade with countries doing business with North Korea, a warning to China, and faulted South Korea for what he called “talk of appeasement.”

In response, Chinese Foreign Ministry spokesman Geng Shuang, told reporters in Beijing on Monday that China regarded as “unacceptable a situation in which on the one hand we work to resolve this issue peacefully but on the other hand our own interests are subject to sanctions and jeopardized. This is neither objective nor fair.”

South Korea’s military said its live-fire exercise was meant to “strongly warn” North Korea. The drill involved F-15 fighter jets and the country’s land-based “Hyunmoo” ballistic missiles firing into the Sea of Japan.

The target was set considering the distance to North Korea’s test site and the exercise was aimed at practicing precision strikes and cutting off reinforcements, Seoul’s Joint Chiefs of Staff said.

Each new North Korean missile and nuclear test gives the country’s scientists invaluable information that allows big jumps in capability. North Korea is thought to have a growing arsenal of nuclear bombs and has spent decades trying to perfect a multistage, long-range missile to eventually carry smaller versions of those bombs.

Both diplomacy and severe sanctions have failed to check the North’s decades-long march to nuclear mastery.

In Washington, Trump, asked by a reporter if he would attack North Korea, said, “We’ll see.” No U.S. military action appeared imminent, and the immediate focus appeared to be on ratcheting up economic penalties, which have had little effect thus far.

In brief remarks after a White House meeting with Trump and other national security officials, Defence Secretary Jim Mattis told reporters that America does not seek the “total annihilation” of North Korea, but then added somberly, “We have many options to do so.”

Mattis said the U.S. will answer any threat from the North with a “massive military response — a response both effective and overwhelming.”

Mattis also said the international community is unified in demanding the denuclearization of the Korean Peninsula and that Kim should know Washington’s commitment to Japan and South Korea is unshakeable.

The precise strength of North Korea’s underground nuclear explosion has yet to be determined. South Korea’s weather agency said the artificial earthquake caused by the explosion was five times to six times stronger than tremors generated by the North’s previous five tests.

Sunday’s detonation builds on recent North Korean advances that include test launches in July of two ICBMs. The North says its missile development is part of a defensive effort to build a viable nuclear deterrent that can target U.S. cities.

North Korea has made a stunning jump in progress in its nuclear and missile programs since Kim rose to power following his father’s death in late 2011. The North followed its two tests of Hwasong-14 ICBMs, which, when perfected, could target large parts of the United States, by threatening to launch a salvo of Hwasong-12 intermediate range missiles toward the U.S. Pacific island territory of Guam in August.

It flew a Hwasong-12 over northern Japan last week, the first such overflight by a missile potentially capable of carrying nuclear weapons, in a launch Kim described as a “meaningful prelude” to containing Guam, the home of major U.S. military facilities, and vowed to launch more ballistic missile tests targeting the Pacific.

Ahead of the North’s test, photos released by the North Korean government showed Kim talking with his lieutenants as he observed a silver, peanut-shaped device that was purportedly a thermonuclear weapon destined for an ICBM. The images were taken without outside journalists present and could not be independently verified. What appeared to be the nose cone of a missile could also be seen in one photo, and another showed a diagram on the wall behind Kim of a bomb mounted inside a cone.

The Arms Control Association in the United States said the explosion appeared to produce a yield in excess of 100 kilotons of TNT equivalent, which it said strongly suggests North Korea tested a high-yield but compact nuclear weapon that could be launched on a missile of intermediate or intercontinental range.

Beyond the science of the blast, North Korea’s accelerating push to field a nuclear weapon that can target all of the United States is creating political complications for the U.S. as it seeks to balance resolve with reassurance to allies that Washington will uphold its decades-long commitment to deter nuclear attack on South Korea and Japan.

That is why some questioned Trump’s jab at South Korea. He tweeted that Seoul is finding that its “talk of appeasement” will not work. The North Koreans, he added, “only understand one thing,” implying military force might be required. The U.S. has about 28,000 troops stationed in South Korea and is obliged by treaty to defend it in the event of war.

Trump also suggested putting more pressure on China, North Korea’s patron for many decades and a vital U.S. trading partner, in hopes of persuading Beijing to exert more effective leverage on its neighbour. Trump tweeted that the U.S. is considering “stopping all trade with any country doing business with North Korea.” Such a halt would be radical. The U.S. imports about $40 billion in goods a month from China, North Korea’s main commercial partner.

Experts have questioned whether North Korea has gone too far down the nuclear road to continue pushing for a denuclearization of the Korean Peninsula, an Obama administration policy goal still embraced by Trump’s White House.

“Denuclearization is not a viable U.S. policy goal,” said Richard Fontaine, president of the Center for a New American Security, but neither should the U.S. accept North Korea as a nuclear power, he said. “We should keep denuclearization as a long-term aspiration, but recognize privately that it’s unachievable anytime soon.”

Associated Press writers Robert Burns and Catherine Lucey in Washington and Kim Tong-hyung in Seoul contributed to this report.</s>South Korea should take a page out of the work of Shakespeare in dealing with North Korea and fight “fire with fire”, experts and media commentators have said in response to the North’s latest nuclear test.



Many in the South are calling for the country to develop its own nuclear weapons as a deterrent independent of the US given uncertain support from Donald Trump.

South Korea hosts about 30,000 US troops and falls under the US nuclear umbrella, but in return is banned from building its own nuclear weapons under a 1974 agreement with Washington.

“As nuclear weapons are being churned out above our heads, we can’t always rely on the US nuclear umbrella and extended deterrence,” the Dong-a Ilbo, South Korea’s second-largest newspaper, said in an editorial.

The US stationed atomic weapons in the South after the 1950-53 Korean war, but withdrew them in 1991 when North and South Korea jointly declared they would make the peninsula nuclear-free.

The editorial said that agreement no longer applied.

“There is no reason for us to cling on to the declaration when it has come to mean the denuclearisation of South Korea, not the denuclearisation of the Korean peninsula,” it said.

North Korea tested its most powerful nuclear bomb on Sunday, producing a 6.3-magnitude earthquake that was felt as far as north-east China.

Almost 60% of South Koreans support starting a nuclear weapons programme, according to a poll in September 2016. Respondents aged 60 and above overwhelmingly supported the idea.

Jeon Yun-gu is just a few years away from his compulsory military service, and despite the rising tensions, the 16-year-old is ready to fight to end the constant threat hanging over the country.

“We should quit just talking and meet North Korea with a firm stand. We should respond to them with the same, they have nuclear weapons, so we should develop our own,” the teenager said. “I think we should attack.”

But others said the first step should be returning US nuclear arms to South Korea, despite Trump accusing the South Korean president, Moon Jae-in, of “appeasement”.

“With the North Korean nuclear threat getting worse, we should bring US tactical nuclear weapons back into South Korea,” Park Byung-kwang, director of centre for north-east Asia at the Institute for National Security Strategy in Seoul, a thinktank affiliated with the country’s intelligence agency.

South Korea had no choice but to work with the US to resolve the deepening crisis, despite Trump’s “unique character”, Park said.

While some in South Korea called for a home-grown nuclear arsenal, Park said it would be impractical given the South has no desire to become a pariah state.

“It would be difficult for South Korea to develop its own nuclear weapons because of international treaties,” Park said. “While sanctions don’t always work on North Korea, the South Korean economy is completely integrated with the rest of the world, making it vulnerable.”

But in rural communities along the demilitarised zone that separates the North and the South, provocations only serve to harden their resolve for a tougher response.

“North Korea has nuclear weapons and are doing experiments despite the entire world’s opposition,” said Woo Jong-il, who lives near the border. “Russia, America, China, they all have it, and even North Korea, a small country in deep poverty has it, so why aren’t we allowed to have it?

“Either America gives us a nuclear bomb or allows us develop one.”

With additional reporting by Soeun Seo in Seoul.</s>SEOUL: North Korea has been condemned internationally for conducting its most powerful nuclear test yet, but, across the border, South Korean President Moon Jae-in is also attracting flak for his policy of pursuing engagement with Pyongyang.

Rebuked by U.S. President Donald Trump, Moon is facing growing calls at home to change course and take a tougher line against North Korea, even from his core support base of young liberals, according to hundreds of comments posted online.

Moon, who swept to power after winning a May 9 election, remains hugely popular but his policy of pursuing both pressure and dialogue with the North is now under scrutiny.

Trump was blunt about the situation facing South Korea, one of Washington's biggest allies in Asia.

"South Korea is finding, as I have told them, that their talk of appeasement with North Korea will not work, they (North Korea) only understand one thing," he said in a tweet on Sunday, after the nuclear test.

Within South Korea, doubts about the "Moonshine" policy of engaging the North have been growing in recent weeks because there has been no change in the pace of the North's ballistic missile testing since Moon took office.

The North twice test-fired intercontinental ballistic missiles in July. Now, despite international warnings, it conducted its sixth and most powerful nuclear test on Sunday.

"You said you will not have dialogue with the North if the North conducts a nuclear test. Keep your word," said a post on the Facebook page of the presidential Blue House from a user named Kim Bojoong.

Moon said during his campaign for the presidency that dialogue would be "impossible for quite some time" if the North were to go ahead with another nuclear test.

However, Moon indicated on Sunday at a National Security Council meeting that he had not given up on talks with the North, a sentiment he repeated on Monday in a telephone call with Japan's Prime Minister Shinzo Abe.

"Pressure must be strengthened until the North comes to the table for dialogue," the presidential Blue House quoted Moon as telling Abe.

In another post on the palace's Facebook page, user Shin Sanggyun said: "We know things are tough for you, mister president, but our response to the North's nuclear pursuit has been rather feeble."

It is time South Korea start considering using its shipbuilding expertise to build nuclear submarines and junior aircraft carriers, Shin said.

The Facebook posts were among hundreds of similar messages left on official social media maintained and monitored by the Blue House including its Twitter account and on the country's largest Naver.com web portal.

Sentiment expressed on South Korea's social media, where users are predominantly people in their 20s and 30s, has been a barometer of political support for Moon, a former human rights lawyer swept to power by an anti-graft movement that brought down his predecessor Park Geun-hye.

Moon's support rating has slipped slightly in recent days but he remains hugely popular.

A public opinion survey by the Realmeter polling agency conducted two days before Sunday's nuclear test and released on Monday showed support for Moon fell by 0.8 percentage point from a week ago to 73.1 percent.

But support among youngsters was strong with Moon getting an 85 percent approval rating among people in their 20s.

South Korea's conservative opposition parties said the Moon government's expectations about North Korea were unrealistic and isolating the country from its allies.

"While the Moon Jae-in government made appeasement gestures and haggled for dialogue despite the North's continued provocations, we have become a nuclear hostage," a senior Liberal Korea Party member, Kim Tae-heum, said on Monday.

Moon's push for dialogue was bound to hit a dead end because Pyongyang never really considered the South as a dialogue partner, said Kim Jun-seok, political diplomacy professor at Dongguk University in Seoul.

"They have to acknowledge us as a partner for talks, but all North Korea wants is to talk with the United States," Kim said.</s>SEOUL, Korea, Republic Of — Following U.S. warnings to North Korea of a “massive military response,” South Korea fired missiles into the sea to simulate an attack on the North’s main nuclear test site on Monday, a day after North Korea detonated its largest-ever nuclear test explosion.

South Korea’s Defence Ministry also said Monday that North Korea appeared to be planning a future missile launch, possibly of an ICBM, to show off its claimed ability to target the United States with nuclear weapons, though it was unclear when this might happen.

The heated words from the United States and the military manoeuvrs in South Korea are becoming familiar responses to North Korea’s rapid, as-yet unchecked pursuit of a viable arsenal of nuclear-tipped missiles that can strike the United States. The most recent, and perhaps most dramatic, advance came Sunday in an underground test of what leader Kim Jong Un’s government claimed was a hydrogen bomb, the North’s sixth nuclear test since 2006.

The United Nations Security Council planned to hold its second emergency meeting about North Korea in a week on Monday to discuss responses to the test.

In Seoul, Chang Kyung-soo, an official with South Korea’s Defence Ministry, told lawmakers on Monday that it was seeing preparations in the North for an ICBM test but didn’t provide details about how officials had reached that assessment. Chang also said the yield from the latest nuclear detonation appeared to be about 50 kilotons, which would mark a “significant increase” from North Korea’s past nuclear tests.

In a series of tweets, U.S. President Donald Trump threatened to halt all trade with countries doing business with North Korea, a warning to China, and faulted South Korea for what he called “talk of appeasement.”

In response, Chinese Foreign Ministry spokesman Geng Shuang, told reporters in Beijing on Monday that China regarded as “unacceptable a situation in which on the one hand we work to resolve this issue peacefully but on the other hand our own interests are subject to sanctions and jeopardized. This is neither objective nor fair.”

South Korea’s military said its live-fire exercise was meant to “strongly warn” North Korea. The drill involved F-15 fighter jets and the country’s land-based “Hyunmoo” ballistic missiles firing into the Sea of Japan.

The target was set considering the distance to North Korea’s test site and the exercise was aimed at practicing precision strikes and cutting off reinforcements, Seoul’s Joint Chiefs of Staff said.

Each new North Korean missile and nuclear test gives the country’s scientists invaluable information that allows big jumps in capability. North Korea is thought to have a growing arsenal of nuclear bombs and has spent decades trying to perfect a multistage, long-range missile to eventually carry smaller versions of those bombs.

Both diplomacy and severe sanctions have failed to check the North’s decades-long march to nuclear mastery.

In Washington, Trump, asked by a reporter if he would attack North Korea, said, “We’ll see.” No U.S. military action appeared imminent, and the immediate focus appeared to be on ratcheting up economic penalties, which have had little effect thus far.

In brief remarks after a White House meeting with Trump and other national security officials, Defence Secretary Jim Mattis told reporters that America does not seek the “total annihilation” of North Korea, but then added somberly, “We have many options to do so.”

Mattis said the U.S. will answer any threat from the North with a “massive military response — a response both effective and overwhelming.”

Mattis also said the international community is unified in demanding the denuclearization of the Korean Peninsula and that Kim should know Washington’s commitment to Japan and South Korea is unshakeable.

The precise strength of North Korea’s underground nuclear explosion has yet to be determined. South Korea’s weather agency said the artificial earthquake caused by the explosion was five times to six times stronger than tremors generated by the North’s previous five tests.

Sunday’s detonation builds on recent North Korean advances that include test launches in July of two ICBMs. The North says its missile development is part of a defensive effort to build a viable nuclear deterrent that can target U.S. cities.

North Korea has made a stunning jump in progress in its nuclear and missile programs since Kim rose to power following his father’s death in late 2011. The North followed its two tests of Hwasong-14 ICBMs, which, when perfected, could target large parts of the United States, by threatening to launch a salvo of Hwasong-12 intermediate range missiles toward the U.S. Pacific island territory of Guam in August.

It flew a Hwasong-12 over northern Japan last week, the first such overflight by a missile potentially capable of carrying nuclear weapons, in a launch Kim described as a “meaningful prelude” to containing Guam, the home of major U.S. military facilities, and vowed to launch more ballistic missile tests targeting the Pacific.

Ahead of the North’s test, photos released by the North Korean government showed Kim talking with his lieutenants as he observed a silver, peanut-shaped device that was purportedly a thermonuclear weapon destined for an ICBM. The images were taken without outside journalists present and could not be independently verified. What appeared to be the nose cone of a missile could also be seen in one photo, and another showed a diagram on the wall behind Kim of a bomb mounted inside a cone.

The Arms Control Association in the United States said the explosion appeared to produce a yield in excess of 100 kilotons of TNT equivalent, which it said strongly suggests North Korea tested a high-yield but compact nuclear weapon that could be launched on a missile of intermediate or intercontinental range.

Beyond the science of the blast, North Korea’s accelerating push to field a nuclear weapon that can target all of the United States is creating political complications for the U.S. as it seeks to balance resolve with reassurance to allies that Washington will uphold its decades-long commitment to deter nuclear attack on South Korea and Japan.

That is why some questioned Trump’s jab at South Korea. He tweeted that Seoul is finding that its “talk of appeasement” will not work. The North Koreans, he added, “only understand one thing,” implying military force might be required. The U.S. has about 28,000 troops stationed in South Korea and is obliged by treaty to defend it in the event of war.

Trump also suggested putting more pressure on China, North Korea’s patron for many decades and a vital U.S. trading partner, in hopes of persuading Beijing to exert more effective leverage on its neighbour. Trump tweeted that the U.S. is considering “stopping all trade with any country doing business with North Korea.” Such a halt would be radical. The U.S. imports about $40 billion in goods a month from China, North Korea’s main commercial partner.

Experts have questioned whether North Korea has gone too far down the nuclear road to continue pushing for a denuclearization of the Korean Peninsula, an Obama administration policy goal still embraced by Trump’s White House.

“Denuclearization is not a viable U.S. policy goal,” said Richard Fontaine, president of the Center for a New American Security, but neither should the U.S. accept North Korea as a nuclear power, he said. “We should keep denuclearization as a long-term aspiration, but recognize privately that it’s unachievable anytime soon.”

Associated Press writers Robert Burns and Catherine Lucey in Washington and Kim Tong-hyung in Seoul contributed to this report.</s>North Korea says it's developed a "super explosive" hydrogen bomb that fits on an intercontinental ballistic missile, according to multiple media reports citing the country's state news agency.

During a visit to the country's Nuclear Weapons Institute, North Korean leader Kim Jong Un watched as the purported H-bomb was loaded into a new ICBM.

Photos released by the Korean Central News Agency show Kim observing a silver, bulbous metal casing. KCNA claims it's a "homemade" H-bomb with "super explosive power," according the Associated Press:



"The North said in its statement Sunday that its H-bomb 'is a multi-functional thermonuclear nuke with great destructive power which can be detonated even at high altitudes for super-powerful EMP (electromagnetic pulse) attack according to strategic goals.' "Kim, according to the statement, claimed that 'all components of the H-bomb were homemade ... thus enabling the country to produce powerful nuclear weapons as many as it wants.' "



In its report, KCNA (via Xinhua, China's official news agency) also said the North Korean leader "guided the work for nuclear weaponization on the spot," as part of "the final-stage research and development for perfecting the state nuclear force."

Following the country's claim of an accelerated nuclear arsenal, President Trump spoke with Japanese Prime Minister Shinzo Abe about efforts to maximize pressure on North Korea.

"The two leaders reaffirmed the importance of close cooperation between the United States, Japan, and South Korea in the face of the growing threat from North Korea," the White House says. "President Trump noted that he looks forward to continued trilateral coordination on the margins of the United Nations General Assembly."

The conversation on Saturday, as Trump was returning from flood-ravaged Louisiana, is the third time the two leaders have spoken since Tuesday, NPR's Scott Horsley reports.

The North test-fired two long-range missiles in July, driving the United Nations Security Council to adopt a resolution last month to impose new sanctions on Pyongyang.

In response to the heightened sanctions, Pyongyang said it was ready with "ultimate measures". A day later, President Trump threatened to meet North Korea with "fire and fury."

But as NPR's Elise Hu reported, Jenny Town, the assistant director of the U.S.-Korea Institute at John Hopkins' School of Advanced International Studies says a policy of increasing pressure is misconstrued as "hostility," which, Town argues, "justifies its need for nuclear weapons."

As the Two-Way reported last month, U.S. intelligence analysts believe North Korea has already developed a warhead that can be placed on its ballistic missiles, including an ICBM capable of reaching U.S. territory.</s>A hydrogen bomb is a highly sophisticated weapon capable of achieving thousands of kilotons of explosive yield. In comparison, the last and most powerful of North Korea’s five nuclear tests, conducted in September 2016, produced an explosive yield of only 10 to 15 kilotons, about the same as the nuclear blast in Hiroshima, Japan, at the end of World War II, according to officials and analysts.

“North Korea appears to have a family of relatively reliable, miniaturized fission weapons with the destructive force rivaling the size of the Hiroshima blast that can use plutonium or weapon-grade uranium and fit on a number of ballistic missiles,” David Albright, president of the Washington-based Institute for Science and International Security, said during congressional testimony last September.

But Mr. Albright said “it is reasonable to skeptically accept that North Korea is working on some type of thermonuclear device, likely one aimed at using thermonuclear materials to significantly boost the yield of a fission device.” His institute has predicted that “in a worst-case assessment,” North Korea could field a crude thermonuclear weapon with a yield approaching 100 kilotons soon after 2020, or possibly sooner.

North Korea’s claim came just days after it sent a ballistic missile over Japan, escalating recent tensions over its pursuit of nuclear missiles. Mr. Trump has threatened to unleash “fire and fury” on the North if it continues to threaten the United States with a nuclear weapon.

Bombastic threats and exaggerated claims have long been part of North Korea’s domestic propaganda and its strategy for dealing with its enemies. But some analysts said that the outside world has long underestimated Pyongyang’s determination to build a reliable nuclear force and needed to pay more attention to its latest claim.

“Disbelieve at your own peril,” said Lee Sung-yoon, a Korea expert at the Fletcher School of Law and Diplomacy at Tufts University. “Trump should remember: It took China only three years to go from its first atom bomb test, in 1964, to to its first hydrogen bomb test, in 1967, 50 years ago.”

But high-ranking United States officials have said that North Korea still has key obstacles to overcome before it can field a nuclear-tipped intercontinental ballistic missile capable of threatening the American mainland.</s>WASHINGTON — North Korea’s detonation of a sixth nuclear bomb on Sunday prompted the Trump administration to warn that even the threat to use such a weapon against the United States and its allies “will be met with a massive military response.’’

The test — and President Trump’s response — immediately raised new questions about the president’s North Korea strategy and opened a new rift with a major American ally, South Korea, which Mr. Trump criticized for its “talk of appeasement” with the North.

The underground blast was by far North Korea’s most powerful ever. Though it was far from clear that the North had set off a hydrogen bomb, as it claimed, the explosion caused tremors that were felt in South Korea and China. Experts estimated that the blast was four to sixteen times more powerful than any the North had set off before, with far more destructive power than the bombs dropped on the Japanese cities of Hiroshima and Nagasaki during World War II.

Yet after a day of meetings in the Situation Room involving Mr. Trump and his advisers, two phone calls between the president and Prime Minister Shinzo Abe of Japan, and even demands from some liberal Democrats to cut off North Korea’s energy supplies, Mr. Trump’s aides conceded that they faced a familiar conundrum.</s>WASHINGTON, United States — The United States warned Sunday it could launch a “massive military response” to threats from North Korea following Pyongyang’s provocative detonation of what it claimed was a miniaturized hydrogen bomb.

The comments from defense secretary Jim Mattis came after President Donald Trump called an emergency meeting of his national security advisers to discuss what was an unexpectedly powerful nuclear test said to exceed in magnitude the atomic bombing of Hiroshima, Japan.

Mattis told reporters: “Any threat to the United States or its territories, including Guam, or our allies will be met with a massive military response, a response both effective and overwhelming.

“We are not looking to the total annihilation of a country, namely North Korea. But as I said, we have many options to do so,” he added.

Trump had earlier denounced the test, tweeting that the time for “appeasement” was over and threatening drastic economic sanctions, including “stopping all trade with any country doing business with North Korea.”

US monitors measured a powerful 6.3-magnitude earthquake near the North’s main testing site, felt as far as parts of China, with an aftershock possibly caused by the collapse of a tunnel at the site.

The North hailed its test of what it described as a hydrogen bomb designed for a long-range missile as “a perfect success.”

Pyongyang residents celebrated as a jubilant television newsreader hailed the “unprecedentedly large” blast; she said it had moved the country closer to “the final goal of completing the state nuclear force.”

Neighboring South Korea reacted by conducting a live-fire exercise simulating an attack on the North’s nuclear site, state news agency Yonhap reported, hitting “designated targets in the East Sea” with missiles and F-15K fighter jets.

The South’s military said the range to the simulated targets were equivalent to the North’s Punggye-ri nuclear test site in its northeastern province.

The exercise came after South Korean President Moon Jae-In, once an advocate of dialogue with the North, called for the “strongest punishment,” joining a chorus of international condemnation of Pyongyang’s sixth nuclear test including from China.

Russian President Vladimir Putin said the test “torpedoes the global non-proliferation regime, violates UN Security Council resolutions” and threatens regional peace, while adding, in a phone call to Japanese Prime Minister Shinzo Abe, that the crisis “should be resolved only by political and diplomatic means.”

And UN Secretary General Antonio Guterres condemned the test as “profoundly destabilizing,” while the Security Council will hold an emergency meeting on Monday.

Hours before the test, the North released images of Kim at his country’s Nuclear Weapons Institute, inspecting the device it called a “thermonuclear weapon with super explosive power” entirely made “by our own efforts and technology,” according to the Korean Central News Agency.

A series of US and United Nations-backed sanctions seem to have had little effect on Pyongyang.

But US Treasury Secretary Steven Mnuchin said Sunday his department was preparing potent new measures that would “cut off North Korea economically.”

“I’m going to draft a sanctions package and send it to the president for his strong consideration that anybody that wants to do trade or business with them will be prevented from doing trade or business with us,” Mnuchin said on “Fox News Sunday.”

While the United States has virtually no trade with the North, the burden of sanctions such as Mnuchin described would fall heavily on China, which buys about 90 percent of North Korean exports.

In Seoul, President Moon Jae-In called for new United Nations sanctions to “completely isolate North Korea.” He said the South would discuss deploying “the strongest strategic assets of the US military” — a possible reference to tactical nuclear weapons, which the US withdrew from South Korea in 1991.

While US Secretary of State Rex Tillerson spoke by phone with his Asian counterparts, US and South Korean military chiefs also conferred.

Seoul’s defense ministry said the respective chairmen of the joint chiefs of staff — General Jeong Kyeong-Doo and General Joseph Dunford — had “agreed to prepare a South Korea-US military counteraction and to put it into action at the earliest date.”

South Korean experts said the tremor near the North’s main test site was five to six times stronger than that from a 10-kiloton test a year ago.

Pyongyang raised tensions in July with two successful tests of an ICBM which apparently brought much of the US mainland within range.

Last week, it fired a missile over Japan.

Jeffrey Lewis of website armscontrolwonk said Sunday’s blast clearly was “a staged thermonuclear weapon,” representing a significant advance.

Trump has warned Pyongyang that it faces “fire and fury” and that Washington’s weapons are “locked and loaded.”

But even some Trump advisers say US military options are limited when Pyongyang has the capacity to quickly wipe out much of the South Korean capital Seoul.

Analysts believe Pyongyang’s weapons program is aimed both at self-defense and strengthening its hand in any negotiations with the United States.

“North Korea will continue with their nuclear weapons program unless the US proposes talks,” Koo Kab-Woo of Seoul’s University of North Korean Studies told AFP. CBB
A 6.3 magnitude earthquake is detected near the Punggye-ri Nuclear Test Site in Kilju County, North Korea, after North Korea tests its sixth and most powerful nuclear weapon to date. North Korean state media claims the country tested a hydrogen bomb that can be fitted on an ICBM.