US, South Korea start joint military drills despite North's nuclear threats Tensions are running high on the Korean peninsula where thousands of U.S and South Korean troops are participating in military drills. The annual exercises have Pyongyang enraged as North Korea threatens both the U.S. and Seoul with nuclear strikes. By Hyung-Jin Kim, The Associated Press SEOUL -- South Korea and the United States began annual military drills Monday despite North Korean threats to respond by voiding the armistice that ended the Korean War and launching a nuclear attack on the U.S. After the start of the drills, South Korean officials said their northern counterparts didn't answer two calls on a hotline between the sides, apparently following through on an earlier vow to cut the communication channel because of the drills. Pyongyang has launched a bombast-filled propaganda campaign against the drills, which involve 10,000 South Korean and about 3,000 American troops, and last week's U.N. vote to impose new sanctions over the North's Feb. 12 nuclear test. Analysts believe that much of that campaign is meant to shore up loyalty among citizens and the military for North Korea's young leader, Kim Jong Un. Pyongyang isn't believed to be able to build a warhead small enough to mount on a long-range missile, and the North's military has repeatedly vowed in the past to scrap the 1953 armistice. North Korea wants a formal peace treaty, security guarantees and other concessions, as well as the removal of 28,500 U.S. troops stationed in South Korea. Still, South Korean and U.S. officials have been closely monitoring Pyongyang's actions and parsing the torrent of recent rhetoric from the North, which has been more warlike than usual. Ahn Young-Joon / AP South Korean soldiers set up barbed-wire fencing during an exercise against possible attacks by North Korea near the border village of Panmunjom in Paju, South Korea, on Monday. North Korea regularly claims South Korea-U.S. drills are a preparation for invasion, but Pyongyang has signaled more worry about the drills that began Monday. The drills follow U.N. sanctions that the North says are the result of U.S. hostility aimed at toppling its political system. North Korea has also warned South Korea of a nuclear war on the divided peninsula and said it was cancelling nonaggression pacts. Under newly inaugurated President Park Geun-hye, South Korea's Defense Ministry, which often brushes off North Korean threats, has looked to send a message of strength in response to the latest threats. The ministry warned Friday that the North's government would "evaporate from the face of the Earth" if it ever used a nuclear weapon. The White House also said the U.S. is fully capable of defending itself against a North Korean ballistic attack. North Korea has said the U.S. mainland is within the range of its long-range missiles, and an army general told a Pyongyang rally last week that the military is ready to fire a long-range nuclear-armed missile to turn Washington into a "sea of fire." North Korea threat of nuclear attack predictable but worrisome UN passes sanctions despite North Korea threats North Korea warns of 'miserable destruction' over drills This story was originally published on Mon Mar 11, 2013 7:48 AM EDT