North Korea threatened Tuesday to scrap the armistice which ended the Korean War in 1953, citing US moves to impose sanctions for its nuclear test and tensions over South Korean-US exercises. The threat came amid reports from the United Nations that China and the United States have reached agreement on new measures to punish the North for last month\'s atomic weapons test. The North\'s military said it could launch a \"precise\" strike anytime, unrestrained by the armistice. It also warned it could mount a strike with atomic weapons to counter any US nuclear threat. In a statement on official media, the military called the joint exercise a \"most blatant\" provocation and slammed a \"vicious\" scheme by the US and its allies to push for tougher United Nations sanctions. The armistice that ended the 1950-53 war will be \"completely\" nullified from March 11, when the South Korean-US exercise gets into full swing in the South, the North said. An annual exercise known as Foal Eagle began on March 1 and will run until April 30, involving more than 10,000 US troops along with a far greater number of South Korean personnel. Separately, US and South Korean troops will stage a largely computer-simulated joint exercise called Key Resolve from March 11-21. The United States has based troops in the South since the war and the force currently numbers 28,500. Pyongyang habitually denounces such drills as a provocative rehearsal for invasion but Seoul and Washington insist they are defensive in nature. The North said it would cut off a military hotline in the truce village of Panmunjom, which straddles the heavily fortified border with South Korea. The armistice was never followed by a peace treaty and the combatants in the Korean conflict have remained technically at war. The hotline has been used by North Korean and US officers to prevent accidental conflicts. The North in the past has threatened to scrap the armistice at times of high tension. Pyongyang said the February 12 nuclear test, its third and most powerful, was a response to tightened UN sanctions imposed after its long-range rocket launch last December. But the underground blast brought strong international criticism even from ally China. The Security Council presidency was to call a closed-door meeting for 11:00 am (1600 GMT), at which US and Chinese diplomats would tell the other 13 council members of progress in their talks. \"There won\'t be a vote on Tuesday, but it could come soon. This is a sign that a draft resolution is about to be handed out,\" a UN diplomat told AFP on condition of anonymity. Details of the proposed new sanctions resolution were not immediately available. The North is already subject to a range of sanctions from the world body for its missile and nuclear tests in 2006 and 2009.