US presses for N. Korea sanctions vote at UN

But ahead of a council meeting to discuss the proposed measures, the isolated North threatened to scrap an armistice which halted the 1950-53 Korean War, a move that would surely heighten tensions.

After reaching an agreement with China, the United States distributed a draft resolution setting out new measures at the closed meeting.

"It looks a good draft," said Mark Lyall Grant, UN ambassador for Britain, one of five permanent members of the council.

"The action includes financial sanctions aimed at restraining the North's nuclear program," said one envoy at the meeting. Details were not immediately made public however.

The sanctions would be under Chapter VII of the UN Charter, diplomats said. This is used in cases considered the most serious threat to international peace.

"There won't be a vote on Tuesday, but it could come soon," a UN diplomat told AFP on condition of anonymity.

Chinese foreign ministry spokeswoman Hua Chunying refused to be drawn on details of any new sanctions, speaking to reporters in Beijing.

"We have made it clear that China is supportive of a proper and moderate response from the Security Council and we believe the reaction should be prudent and appropriate and should avoid escalating the situation," she said.

"Relevant action should be conducive to denuclearization, non-proliferation and the peace and stability of the Korean peninsula and the region," she added.

The US ambassador to the United Nations, Susan Rice, has been in talks with her Chinese counterpart, Li Baodong, on sanctions since North Korea staged its third nuclear test to near universal condemnation.

Within hours of the blast, all 15 council members backed a statement which said the North was in "grave violation" of existing UN resolutions and that they would go ahead with an earlier threat to take "significant action" against the North.

China, ever fearful of threats to stability on its border with North Korea, has been reluctant to agree to tough new action, diplomats said. "There have been tough talks between the United States and China," said a UN diplomat.

North Korea said its third nuclear test in seven years was a riposte to "US hostility" shown in the widening of existing UN sanctions following its rocket launch in December last year.

Pyongyang angrily rebuffed the UN steps with a threat to end the historic armistice that has kept the peace on the Korean peninsula for the past six decades.

The North blasted the US moves to impose sanctions and South Korean-US military exercises in a statement reported by official media.

The armistice will be "completely" nullified from March 11, when the South Korean-US exercise gets into full swing, the North said.

The North's military could launch a "precise" strike anytime, unrestrained by the armistice, the statement said. It also warned it could mount a strike with atomic weapons to counter any US nuclear threat.

It 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 North says its long-range missile can now reach US territory. It has angrily warned that it will not be bound by UN resolutions in what diplomats have said is a strong indication that a new nuclear test or rocket launch could be tried.

The Security Council ordered wide-ranging sanctions against the North after its 2006 and 2009 nuclear tests.

In 2006, the council ordered an embargo on arms and material for ballistic missiles against the North. It also banned exports of luxury goods and named individuals and companies to be subject to a global assets freeze and travel ban.

In 2009, the council banned North Korea's weapons exports and ordered all countries to search suspect shipments.

These measures were expanded after the long-range rocket launch in December, which the United States and its allies said was a test of a ballistic missile carrier. The rocket took a satellite into space.