North Korea has warned it is preparing to conduct a third nuclear test and launch long-range rockets as payback for "hostility" from the US, declaring that Pyongyang is prepared to wage "full-fledged confrontation".
China, the country's only ally, has been forced to call for calm and restraint from the regime after the National Defence Committee in Pyongyang said it was conducting a "peaceful satellite mission", which the US claims is a test of long-range missiles.
The move comes two days after the UN Security Council agreed to expand sanctions against North Korea, as a response to a previous rocket launch, in December.
State media agency Korean Central News ran a report which read: "In the wake of desperate efforts on the part of the U.S. and its followers to block the victorious advance of the DPRK, they cooked up a "resolution" of the UN Security Council on Tuesday in wanton violation of the inviolable sovereignty of the DPRK."
North Korea's Foreign Ministry said in a statement: "The hostile forces are seriously mistaken if they think they can bring down the DPRK with sanctions and pressure, and such an attempt will always bring them a disgraceful defeat.
"The DPRK will continuously launch satellites for peaceful purposes to conquer space and become a world-level space power.
"The UNSC should apologize for its crime of seriously encroaching upon the independence of a sovereign state, following the US policy hostile to the DPRK in disregard of the universally recognized international laws, and repeal all the unreasonable "resolutions" at once."
China's Foreign Ministry spokesman Hong Lei called for "calm and restraint" on Thursday, urging the "relevant party" not to take any steps that would raise tensions, according to a Reuters report.
The timing seems deliberate to coincide with US President Barack Obama's inauguration. In 2008, shortly after the new President was sworn in, North Korea conducted similar tests, UN sanctions were applied and a nuclear test followed.
The South Korean news agency Yonhap said that South Korea was stepping up its monitoring of tunnels at North Korea's nuclear weapons test site, and Seoul officials warned a nuclear device could be “ready to detonate on a few days notice, but the decision to go ahead with the test will be a political one.”