North Korea condemns US B-52 bombers training flights U.S. forces in South Korea conduct military training amid tensions on the peninsula after North Korea threatened the U.S. with a pre-emptive nuclear strike. NORTH Korea has condemned training flights by nuclear-capable US B-52 bombers over the Korean peninsula as an "unpardonable provocation" and threatened military action if they continue. The Pentagon says at least one B-52 has flown over South Korea in recent weeks as part of joint South Korea-US military exercises that Pyongyang has denounced as rehearsals for invasion. State TV release video of North Korean youth joining military "It is an unpardonable provocation," a North Korean foreign ministry spokesman said in a statement carried by the official Korean Central News Agency (KCNA) today. North Korea accuses US and South Korea of cyber attacks The US is introducing a strategic nuclear strike means to the Korean peninsula at a time when its situation is inching close to the brink of war. South Korean soldiers walk along an iron fence near a military check point in the border city of Paju. US bolster arsenal against a North Korean strike Military tensions on the Korean peninsula are at their highest level for years, with North Korea - angered by UN sanctions imposed after its nuclear test last month - threatening a second Korean War backed by nuclear weapons. The foreign ministry said Pyongyang was closely watching the ongoing exercises and vowed a ``strong military counteraction, should the strategic bomber make such a sortie to the peninsula again. Pentagon spokesman George Little said on Monday that a B-52 from Andersen Air Force base in Guam flew over South Korea on March 8. South Korea's Yonhap news agency reported that another B-52 sortie was carried out yesterday. A B-52 bomber flies over Osan on March 19, 2013, as part of joint US-SKorea military drills. The US said it was flying training missions of nuclear-capable B-52 bombers over South Korea, in a clear signal to North Korea at a time of escalating military tensions. B-52s have taken part in annual exercises on the peninsula before, but Little said the Pentagon wanted to underline their use this time given the heightened tensions. The flights should be seen as underscoring US commitment and capacity to defend Seoul against an attack from the North, Little said. That message was echoed in Seoul on Monday by visiting Deputy Defense Secretary Ashton Carter, who promised to provide South Korea with every available military resource "offered by the US nuclear umbrella."