Nations are required to give 90 days notice before pulling out of the 1968 Nuclear Nonproliferation Treaty, which has been signed by more than 180 countries. However, North Korea said its withdrawal would take effect Saturday.
In a statement released by its official news agency, Pyongyang said it had no immediate plans to produce nuclear weapons.
"Though we pull out of the NPT, we have no intention to produce nuclear weapons and our nuclear activities at this stage will be confined only to peaceful purposes such as the production of electricity," the three-page statement said.
Pyongyang described its withdrawal from the treaty as an act of "self-defense" because it is "most seriously threatened" by the United States, and warned that it would consider producing nuclear weapons if the U.S. did not stop making "nuclear threats" toward the communist nation.
"If the U.S. drops its hostile policy to stifle the [Democratic People's Republic of Korea] and stops its nuclear threat to it, the DPRK may prove through a separate verification between the DPRK and the U.S. that it does not make any nuclear weapons," the statement said.
In a rare press conference on Friday, North Korean Ambassador to the U.N. Pak Gil Yon said his country would not begin making nuclear weapons "at this stage," but warned "future developments will entirely depend on the United States."
The U.S. condemned the withdrawal Friday afternoon, with State Department spokesman Richard Boucher saying it "represents a further escalation of North Korea's defiance of the international consensus in support of a Korean Peninsula free of nuclear weapons."
Vice President Dick Cheney said the announcement "is of serious concern to North Korea's neighbors and to the entire international community."
"Their actions threaten to undermine decades of nonproliferation efforts and only further isolate the regime," Cheney said in a speech to a business group. "North Korea's relations with the entire international community depend on their taking prompt and verifiable action to completely dismantle their nuclear weapons program," Cheney said in a speech to a business group.
Britain, France, Russia, Germany and Sweden also denounced the North Korean decision, the Associated Press reports. Japan called on North Korea to reconsider its decision, while South Korea said the crisis was a matter of "life and death."
After learning of the announcement, President Bush spoke by telephone with Chinese leader Jiang Zemin, whose country is considered North Korea's closest ally.
According to White House spokesman Ari Fleischer, Mr. Bush told the Chinese president that Washington had "no hostile intentions toward North Korea" and was seeking a peaceful solution to the standoff. During the conversation, Jiang "reiterated China's commitment to a non-nuclear Korean peninsula," Fleischer said.
Meanwhile, two North Korean diplomats met with New Mexico Gov. Bill Richardson in Santa Fe. Richardson served as the Energy Secretary during the Clinton administration and was a former U.S. ambassador to the U.N. and had experience working with North Korea. Richardson also visited the communist country on two diplomatic missions while he was a member of Congress during the 1990s.
At a press conference Friday in Washington, White House spokesman Ari Fleischer said he was unsure if the talks were making progress, but said Richardson would maintain the Bush administration's policy towards North Korea.
"The only message we expect is what America's position is, that we are ready to talk, and that we will not negotiate," Fleischer said.
The North Korean government made a similar withdrawal announcement in 1993, when U.N. officials raised questions about its alleged nuclear weapons program. That potential crisis was resolved with a multinational agreement in 1994 in which North Korea promised to abandon its nuclear arms program in exchange for assistance building a nuclear reactor for energy generation. Pyongyang has since rejected that pact.