North Korea turned over key nuclear weapons documents to a visiting U.S. diplomat Thursday, a senior State Department official said. It was a step toward the Bush administration's goal of a full accounting of the isolated regime's nuclear past.

The official told The Associated Press that the North handed over the records in the capital Pyongyang. The diplomat is to carry them to South Korea later this week. The official spoke on condition of anonymity to describe the outcome of confidential meetings between U.S. envoy Sung Kim and the government of Kim Jong Il.

The documents are detailed technical logs from North Korea's shuttered plutonium reactor. The records will give the U.S. and other outsiders a way to, in effect, check North Korea's mathematics if it finally produces a long-overdue summary of its weapons program.

"They are an important element in the verification of a declaration which will include figures for the amount of plutonium they have produced," the State Department official said. "These documents would help verify those figures are correct."

The paperwork could also build confidence among conservative critics of the recent, relatively flexible U.S. posture toward North Korea, an isolated dictatorship President George W. Bush once termed part of an "axis of evil." The Bush administration is pursuing a comprehensive disarmament deal with the North that requires some congressional approval, and is lobbying to counter criticism that it is giving away the store.

North Korea agreed in recent weeks to blow up the cooling tower at its Yongbyon reactor, a largely symbolic display but one intended to demonstrate good faith in its nuclear talks with the U.S. and four other nations.

U.S. diplomats also appear close to an agreement with the North over distribution of promised U.S. food aid, the State Department official said. The U.S. takes pains to keep the two issues separate, saying food is a humanitarian issue that should not be linked to U.S. goals in other areas, but officials acknowledge that the North may not make the same distinction.

North Korea has relied on foreign aid to feed its 23 million people after its economy was devastated by natural disasters and mismanagement in the mid-1990s. As many as 2 million people are believed to have died from famine.

The food situation in the North has worsened this year after a devastating flood swept the country last summer and South Korea's new conservative government stopped sending aid.

A previous offer of U.S. aid broke down over U.S. demands that it be able to monitor the distribution to ensure it reached the needy. The administration accuses the regime of widespread corruption. The North now seems more receptive to greater U.S. oversight, the official said.

The developments together suggest a better footing for the United States and North Korea after months of rancor and deadlock. Ridding the North of nuclear weapons that threaten Asia and, in theory, the U.S. West Coast, would give the Bush administration a foreign policy victory in its final year.

The United States says North Korea missed a Dec. 31 deadline to list its past plutonium production and provide other information under an agreement struck earlier in 2007. The bargain would give the North economic and political incentives, including removal from a U.S. list of terror-sponsoring nations, in exchange for giving up a weapons program that culminated in a successful nuclear test in 2006.

The North claims it met its obligations, but has also agreed to a new tentative deal to break the impasse. That deal would have the North acknowledge U.S. concerns about an illicit uranium program and alleged sale or transfer of nuclear know-how to other nations but would not require the North to spell everything out.

The deal would set up a system to verify that North Korea is telling the truth and does not restart banned nuclear activities.

Terms of the deal do not satisfy some congressional Republicans whose vote the administration will probably need to provide money promised for weapons disposal and other pledges to the North.