But the White House said it had no new information from the hardline communist nation on when it might provide the declaration, which was due by December 31, 2007 as part of a six-nation, aid-for-denuclearization deal.

"I don't think it's something that you can put a timeframe on. Sooner is better than later, and that's what our negotiators are working toward," spokesman Tony Fratto said when asked how long Washington was willing to wait.

The Washington Times, quoting administration and congressional officials, reported Thursday that Pyongyang has "tentatively agreed to give the United States thousands of records from its key Yongbyon nuclear reactor dating back to 1990."

They were "to complement an expected declaration of its nuclear programs," it said.

The State Department declined to comment on the report but noted that a US team visited Pyongyang last week to discuss the declaration and ways to verify it.

The United States is seeking access to records of the plutonium-producing Yongbyon reactor, as well as samples from toxic waste and the destruction of a "cooling tower" at the Yongbyon complex, the Times quoted officials as saying.

"The administration is trying to work out the arrangements necessary to verify the accuracy of the North Korean declaration," one official said.

Last year, North Korea said that it possessed about 30 kilograms (66 pounds) of plutonium, much less than US intelligence had estimated, reports said.

The North, which blasted a nuclear bomb in October 2006, shut down the Yongbyon plant and is in the process of disabling it under a deal reached with the United States, China, the two Koreas, Japan and Russia.

The final phase of completely dismantling the plant and surrendering all nuclear material will be implemented after it hands over the declaration.

In return for total denuclearization it would receive energy aid, a lifting of bilateral sanctions, the establishment of diplomatic relations with the US and a formal peace treaty.

The US House of Representatives foreign affairs panel has passed legislation allowing the administration to fund North Korea's denuclearization under tight provisions imposed by lawmakers skeptical of Pyongyang's commitments under the six-party deal, Congressional aides said Thursday.

"This authority will support the administration's efforts effectively to verify the DPRK's (North Korea's) declaration and denuclearization of the Korean peninsula under the six-party talks," State Department spokesman Kurtis Cooper told AFP.

"We understand the concerns behind some of the provisions of the bill and we will continue to work closely with Congress on the legislation," he said.

Washington estimates it would need an additional 50 million dollars for fiscal year 2008 and another 360 million dollars the following year to continue North Korea's nuclear disablement, reports have said.

The United States says North Korea's nuclear declaration also must clear up suspicions about an alleged secret uranium enrichment program and North Korea's suspected involvement in the construction of a nuclear plant in Syria.

The North denies both activities. Under a reported tentative deal, it will merely "acknowledge" US concerns about the two issues in a confidential document to the United States.