5 March 2013 Last updated at 10:22 ET 
North Korea celebrated the test as a necessary self-defence victory
The UN Security Council is to hold closed-door talks on North Korea after reports of a US-Chinese deal on new sanctions over its nuclear test.
Unnamed diplomats were quoted as saying the US is expected to circulate a draft resolution to the 15-nation council at its 11:00 (16:00 GMT) meeting.
North Korea carried out its third and most powerful nuclear test in February, sparking worldwide condemnation.
Earlier on Tuesday, Pyongyang warned it may scrap a 60-year Korean ceasefire.
North Korea's military said it would end the truce with South Korea if Seoul continued annual military exercises with the US, which began on Friday.
The Korean War ended with an armistice in 1953 - not a peace treaty - meaning the peninsula is still technically at war.
Similar threats have been made before by the North, which sees the military exercises and pressure over its nuclear programme as acts of aggression.
'Continued hostility' The UN press office announced on Tuesday that Russia, which holds the Security Council presidency, would convene a closed-door session on North Korea.
Diplomats, speaking anonymously, said they expect to see a draft resolution at the session, with a vote on it by the end of the week.
North Korea is already subject to a raft of sanctions affecting individuals and government bodies, restricting financial activities and barring any trade or test of ballistics and nuclear technology.
Continue reading the main story The 1953 cease-fire
The agreement provided for:
- A suspension of open hostilities
- A fixed demarcation line with a four kilometre (2.4 mile) buffer zone ("demilitarisation zone")
- A mechanism for the transfer of prisoners of war
But the US has been pushing for tougher financial restrictions since February's test.
China is North Korea's only ally and its major trading partner. Beijing has been reluctant to support tougher sanctions in the past, citing the impact of potential instability inside its secretive neighbour state. With the recent test, however, its stance appears to have changed.
China declined to give details of a new deal agreed with Washington, but spokeswoman Hua Chunying said: "We have said here many times that China supports the UN Security Council in reacting moderately and explicitly objects to North Korea's nuclear test."
February's nuclear test was the first of its kind under new leader Kim Jong-un, who took over the leadership after his father Kim Jong-il died in December 2011.
Pyongyang said the test was a "self-defensive measure" made necessary by the "continued hostility" of the US.
Nuclear test monitors based in Vienna say the underground explosion had double the force of the last test, in 2009, despite the use of a device said by the North to be smaller.
North Korea claimed that a "miniaturised" device had been tested, increasing fears that Pyongyang had moved closer to building a warhead small enough to arm a missile.
The test came weeks after Pyongyang successfully used a rocket to put a satellite into space, a move condemned by the UN as a banned test of missile technology.
