TOKYO — North Korea took a step on Thursday toward reintegration into the world community and rapprochement with the United States by submitting for outside review a long-delayed declaration of its nuclear program.

The Bush administration almost immediately announced it would remove the country it once described as part of the “axis of evil” from the State Department’s list of state sponsors of terrorism.

The 60-page declaration from North Korea, one of the world’s most isolated and impoverished nations, was expected to describe in previously undisclosed detail its capabilities in nuclear power and nuclear weapons — meeting a major demand of the United States and other countries that consider the North a dangerous source of instability.

“This can be a moment of opportunity for North Korea,” said President Bush, announcing the declaration at the White House. “If it continues to make the right choices it can repair its relationship with the international community.”

With issues like Iran and Iraq still unresolved, the Bush administration considers the North Korean declaration a notable diplomatic achievement in the waning months of the current presidency.

Mr. Bush said in the principle of “action for action,” the United States would lift some restrictions on commercial dealings with North Korea and within 45 days end its designation of North Korea as a state sponsor of terrorism. “Today we have taken a step toward a nuclear free Korean peninsula,” he said.

American officials expected that the declaration, which had been due at the end of last year, would provide important details about North Korea’s nuclear facilities and programs, including the amount of plutonium produced at its nuclear reactor in Yongbyon.

Partly to deflect criticism from hard-line critics in Washington that the current deal was too soft on North Korea, American officials have emphasized the importance of the information on plutonium. The North is believed to have produced enough weapons-grade plutonium at its reactor in Yongbyon to make as many as half a dozen bombs.

But, significantly, the North’s declaration was not expected to reveal details on three critical points: the nuclear bombs the North has already produced; its alleged attempts to produce nuclear arms by secretly enriching uranium, which triggered the ongoing crisis in 2002; and accusations that the North helped Syria build a nuclear plant.

Some of the missing details, particularly on the North’s existing nuclear bombs, are expected to be revealed at the next stage of the step-by-step agreement when Pyongyang is bound to dismantle and abandon its weapons.

China, which has been the host of the six-nation talks on the North’s nuclear program, said Thursday afternoon that the North was submitting its declaration. The White House confirmed the exchange shortly afterward and said that it would remove North Korea from the terrorism list and thus make it eligible for aid and assistance, a goal long sought by the cash-starved country.

“I do think it’s important to note that if we can verifiably determine the amount of plutonium that has been made, we then have an upper hand in understanding what may have happened in terms of weaponization,” Secretary of State Condoleezza Rice said after arriving in Kyoto, Japan, on Thursday for a meeting of the Group of Eight industrialized powers.

Ms. Rice added that the declaration was “a natural step on the way to dealing verifiably with the devices or weapons themselves.”

Choe Jin Su, the North Korean ambassador to Beijing, submitted the report to Wu Dawei, the main Chinese envoy to the six-nation talks, South Korean government officials said.

“This declaration completes this stage of the talks, as far as plutonium-related activities are involved,” said Yoon Duk-min, a senior analyst at the Institute for Foreign Affairs and National Security in Seoul. “But as far as negotiating on the other issues, that will have to be handled by the next administration in Washington. There’s realistically not enough time left for the Bush administration.”

“And North Korea, which got what it wanted by being removed from the list of state sponsors of terrorism, is probably waiting for the next administration,” Mr. Yoon said.

The North was scheduled to follow up on Friday by blowing up a cooling tower at its Yongbyon reactor, about 60 miles north of Pyongyang.

Pyongyang has invited officials and television networks from the five nations negotiating with the North on its nuclear program — the United States, China, Japan, South Korea and Russia — to witness the tower’s demolition. But the destruction, which is expected to be broadcast live, will be largely symbolic since the reactor was disabled late last year under American supervision.

The White House spokeswoman, said U.S. officials will verify the North’s declaration over the next 45 days, a process that could eventually remove North Korea from terrorism list, and make the North eligible for American aid and for loans from international institutions like the World Bank.

The North was initially put on the list two decades ago after its agents blew up a South Korean airliner carrying 115 passengers.

The United States said it would also lift sanctions imposed on North Korea as part of the World War I era Trading with the Enemy Act, a move that would leave only Cuba on the list.

Thursday’s developments marked the culmination of a change in the Bush administration’s policy towards the North. After years of confronting the North — Mr. Bush famously said he “loathed” the North’s leader, Kim Jong-il, and described him as a “pygmy” — Mr. Bush allowed Christopher R. Hill, an assistant secretary of state, to start engaging in full-fledged negotiations with Pyongyang in early 2007, under the guidance of Ms. Rice.

The about-face drew fire from hawks in the administration, centered around Vice President Dick Cheney, and also from Japan, which had sometimes taken an even harder line on the North.

Japanese politicians like former Prime Minister Shinzo Abe complained this week that the United States should not remove North Korea from the terrorism list until there is a full accounting of Japanese citizens abducted by North Korea in the 1970’s. Doing so would harm relations between Tokyo and Washington, Mr. Abe warned.

On Wednesday, President Bush talked to Japan’s Prime Minister Yasuo Fukuda by telephone and assured him that he had not forgotten about the abductees.

On Thursday, Mr. Fukuda, a moderate, rejected criticism inside Japan that Tokyo now had little leverage over Pyongyang because of its removal from the terrorism list. He said working with the United States “will be really necessary to realize the denuclearization and, at the same time, pave the way for solving the abduction issue, which is a major task for our country.”

North Korea recently agreed to reinvestigate the abductions, while Japan said it would lift some minor sanctions against the North. But so far, Tokyo has refused to contribute energy aid to the North as part of the six-nation nuclear agreement, and Japanese participation is expected to become crucial as considerably more assistance has been promised to the North.

Both Mr. Bush and Ms. Rice addressed the strong sentiment in Japan that the Bush administration had abandoned Tokyo, its most important ally in Asia, for the sake of reaching an imperfect agreement with the North.

“We’re continuing to expect the North Koreans to take this issue seriously because it is a major issue for Japan and it’s a major issue for the United States,” Ms. Rice said of the abductions issue.

In Beijing, the chief negotiator for China, Vice Foreign Minister Wu Dawei, said at a news conference that North Korea “will submit its nuclear declaration to the chair of the six-party talks, and that the United States will implement its obligations to remove the designation” of North Korea as a state sponsor of terrorism and to end economic sanctions based on a U.S. federal law that restricts trade with any nations deemed hostile to the U.S.

Mr. Wu said all the nations have agreed the declaration must first be verified according to a set of principles that have already been established. A monitoring process will be set up to ensure that all governments involved in the talks follow through with their promises, including pledges of nonproliferation as well as economic and energy assistance, he added. The move by North Korea shows that the talks have “made positive progress,” he said.

Mr. Wu made the announcement by reading from a brief statement and declined to answer questions afterward, instead walking quickly out of the regular news briefing room at the Foreign Ministry.

Norimitsu Onishi reported from Tokyo and Edward Wong reported from Beijing. Reporting was contributed by Helene Cooper in Washington and Graham Bowley in New York.