Updated

North Korea defiantly told the world Thursday it does have nuclear weapons and that it's not interested in restarting disarmament talks anytime soon.

The communist nation argued it needs protection against what it considers an increasingly hostile United States.

Pyongyang's pronouncement was the first time it publicly confirmed what other nations suspected, but its claim could nevertheless not be independently verified.

The announcement raised the stakes in North Korea's two-year-old nuclear confrontation with the U.S., and posed a grave challenge to President Bush, who began his second term with a vow to end the Stalinist state's nuclear program through a resumption of the suspended "six-nation" talks (search).

"We ... have manufactured nukes for self-defense to cope with the Bush administration's ever more undisguised policy to isolate and stifle the [North]," the North Korean Foreign Ministry said in a statement carried by the state-run Korean Central News Agency (search).

Officials at the White House downplayed North Korea's words, saying that country has history of making blustering statements. North Korean officials had already privately told those countries involved in the six-way talks that they had nuclear weapons; Thursday was the fist public announcement.

"We've heard this kind of rhetoric before," White House spokesman Scott McMcClellan told reporters aboard Air Force One. "North Korea's words and actions will only deepen their international isolation."

McClellan said the intelligence community believes that North Korea has developed nuclear weapons since about 1994 but that the other countries in the region believe Pyongyang should be a nuclear-free zone. The spokesman also reiterated America's commitment to the six-party talks.

U.N. Secretary General Kofi Annan (search) said he believed North Korea could be brought back to into negotiations.

"I expect that with efforts by other countries, North Korea could be brought back to the table. I would urge [other countries] to engage North Korea," Annan told reporters in London after meeting British Foreign Secretary Jack Straw (search).

North Korea expelled the last U.N. nuclear monitors in late 2002 and has never tested a nuclear bomb, although international officials have long suspected it has one or two nuclear bombs and enough fuel for several more.

Secretary of State Condoleezza Rice (search) said North Korea should return to disarmament talks and avoid a path toward further international isolation. She said the world "has given them a way out and we hope they will take that way out."

"The North Koreans have been told by the president of the United States that the United States has no intention of attacking or invading North Korea," Rice told a news conference in Luxembourg. "There is a path for the North Koreans that would put them in a more reasonable relationship with the rest of the world."

Just four hours before the Korean Central News Agency transmitted the pullout statement, a top Bush administration official told reporters in Tokyo that North Korea's return to the nuclear talks was expected by all other participants in the six-party talks: the United States, Japan, South Korea, Russia and China.

"The onus is really on North Korea," said John R. Bolton (search), undersecretary of state for arms control and international security. His remarks were reported in The New York Times.

Referring to North Korea's bomb-making capability, Bolton added: "The absence of progress in six-party talks means they are making further progress toward their increased capability."

Bush has so far refused North Korea's request for one-on-one talks with the United States but has allowed sideline discussions during the six-way talks.

U.S. Must Keep Its Cool

The North's U.N. envoy said last year that the country had "weaponized" plutonium from its pool of 8,000 spent nuclear-fuel rods. Those rods contain enough plutonium for several bombs.

North Korea's "nuclear weapons will remain [a] nuclear deterrent for self-defense under any circumstances," the ministry said Thursday.

It added that Washington's alleged attempt to topple the North's regime "compels us to take a measure to bolster its nuclear weapons arsenal in order to protect the ideology, system, freedom and democracy chosen by its people."

"The fact that North Korea has nuclear weapons is not any news. It was just a question of how many," House Democratic Leader Nancy Pelosi of California said Thursday, adding that she still supports the six-party talks. "The administration has not paid enough attention to North Korea. The North Koreans know that we are otherwise occupied, and they've taken the liberty to be brazen."

"I don't think they're saying they'll use them," Rep. Tom Lantos (search), the ranking Democrat on the House International Relations Committee, told FOX News. "I think it's very important for us to keep our cool."

Lantos said China must be told of the importance of the leverage it has with North Korea. China supplies the impoverished country with food and energy, among other things, and is regarded as key to bringing North Korea back to the negotiating table.

"Without Chinese help, the country would implode," Lantos said. "The Chinese must understand it is not in their interest to have a nuclear Korean peninsula."

Sen. Saxby Chambliss (search), R-Ga., who serves on the Senate Armed Services Committee, told FOX News that North Korea's announcement is further evidence that the country's government has "unstable leadership."

"That's what the real problem is relative to them possessing a nuclear weapon — what do they intend to do with it?" Chambliss said. "It's a very serious situation, and it's unfortunate they've decided to pull out of the multinational talks."

Chambliss said North Korea's neighbors have the most to lose.

"It's a serious situation ... and it's one we need to continue to deal with diplomatically," he added.

Since 2003, the six nations have held three rounds of talks in Beijing aimed at getting the North to give up weapons development in return for economic and diplomatic rewards. No significant progress has been made.

A fourth round scheduled for last September was canceled when North Korea refused to attend, citing what it called "hostile" U.S. policy.

South Korea said Thursday the North's decision to stay away from talks was "seriously regrettable."

Foreign Ministry spokesman Lee Kyu-hyung said, "we again declare our stance that we will never tolerate North Korea possessing nuclear weapons."

North Korea: No More Talking

On Thursday, North Korea said it decided not to rejoin disarmament talks after studying Bush's inaugural and State of the Union (search) speeches and after Rice labeled North Korea an "outpost of tyranny."

"We have wanted the six-party talks," the foreign ministry's statement read, "but we are compelled to suspend our participation in the talks for an indefinite period till we have recognized that there is justification for us to attend the talks and there are ample conditions and atmosphere to expect positive results from the talks."

Still, North Korea said it retained its "principled stand to solve the issue through dialogue and negotiations and its ultimate goal to denuclearize the Korean Peninsula remain unchanged."

In Vienna, a spokesman for the International Atomic Energy Agency (search) said, "North Korea remains our single highest priority."

"We know they have raw materials to build nuclear weapons. We also know that they have a delivery system and they've expressed their intentions to have a nuclear arsenal," spokesman Mark Gwozdecky said.

Japan's top government spokesman said he wanted to confirm the North's intentions.

"They have used this sort of phrasing every so often. They didn't say anything particularly new," Chief Cabinet Secretary Hiroyuki Hosoda said.

For months, North Korea has lashed out at what it calls U.S. attempts to demolish the regime of leader Kim Jong Il (search) and meddle in the human rights situation in the North. Washington has said it wants to resolve the nuclear talks through dialogue.

In his Jan. 20 inaugural speech, Bush vowed that his new administration would not shrink from "the great objective of ending tyranny" around the globe.

In his State of the Union address earlier this month, Bush only mentioned North Korea once, saying Washington was "working closely with governments in Asia to convince North Korea to abandon its nuclear ambitions." Three years ago, Bush branded North Korea part of an "axis of evil" with Iran and Iraq.

North Korea quit the Nuclear Nonproliferation Treaty (search) in early 2003 and restarted its plutonium-based nuclear weapons program, which had been frozen under a 1994 agreement.

FOX News' Molly Henneberg and Liza Porteus and The Associated Press contributed to this report.