North Korea declared Tuesday that it will restart its partially disabled nuclear facilities and will no longer take part in the so-called six-party disarmament talks on its nuclear weapons program.
The International Atomic Energy Agency said North Korea is telling its inspectors at those facilities to leave.
The moves came in response to a statement issued Monday by the 15-member U.N. Security Council condemning North Korea's April 5 rocket launch and calling for economic sanctions against North Korea to be fully enforced.
A defiant statement from the North Korean Foreign Ministry in Pyongyang and read on North Korean television said the six-party talks had "lost the meaning of their existence, never to recover."
Fulfilling Earlier Threats
North Korea, following through on earlier threats to take action if it came under criticism from the Security Council, said it will no longer participate in the six-party talks nor will it be bound to any agreements made in the negotiations.
North Korea also said it will restore its nuclear facilities at Yongbyon to full working order and resume reprocessing plutonium there away from the prying eyes of IAEA inspectors.
The Security Council on Monday demanded an end to North Korea's rocket launches and said it would expand sanctions. The United States and Japan wanted a stronger resolution condemning the launch and imposing new sanctions.
But facing opposition from China and Russia, which have the power of the veto, the Security Council issued the far weaker council statement.
That appeared to make no difference to North Korea, which called the action an unbearable insult.
White House Calls Threat 'Provocative'
The White House on Tuesday called on North Korea to end its provocative threats and respect the will of the international community. Withdrawing from the six-party talks is "a serious step in the wrong direction," presidential press secretary Robert Gibbs said.
China and Russia quickly sought to keep the situation calm.
Russian Foreign Minister Sergei Lavrov called the Security Council statement well-balanced, and he appealed to North Korea and the other parties involved in the nuclear disarmament talks to remain committed to the process.
North Korea claims that the April 5 rocket launch successfully put a satellite in orbit, but the U.S., South Korea and Japan said that all stages of the rocket fell into the Pacific Ocean and that nothing was put in orbit.
The rocket, known as the Taepodong-2, flew over Japan, where the threat from North Korean missiles is felt acutely.
Yasuhisa Kawamura, a spokesman for the Japanese government, said North Korea should not use the Security Council action as an excuse to walk away from the negotiating table.
"The launch of the missile this time has posed a threat to the entire international community; therefore the unanimous voice issued by the Security Council this time is quite important," Kawamura said.
North Korea has threatened to walk away from the talks and restart its nuclear facilities before. It routinely uses brinksmanship as a tactic in negotiations.
But David Straub of Stanford University, a former State Department Korea Desk director, believes North Korea now will do exactly what it's threatening to do.
"I think they'll probably do everything that they've said in there, including restarting the nuclear facilities at Yongbyon and reprocessing some more fissile material, and probably if they can make a few additional nuclear materials," he said.