TOKYO - North Korea could disable its nuclear facilities by the end of this year under a tentative accord reached in six-party negotiations over its atomic programmes, diplomatic sources said on Monday.

Talks in Beijing between the two Koreas, the United States, China, Japan and Russia ended on Sunday to allow delegates to discuss a joint statement, which includes details on the next phase of the denuclearisation plan, with their governments.

Under the draft agreement, North Korea would disable three facilities at its Yongbyon nuclear complex and declare its nuclear programmes -- including its uranium enrichment plans -- by the end of the year, diplomatic sources in Tokyo told Reuters.

The three facilities were a five-megawatt atomic reactor capable of extracting plutonium from nuclear fuel used in the reactor, a fuel fabrication facility and a research lab, said the sources with full knowledge of the six-party talks.

The document laid out "detailed procedures and methods" for disabling the nuclear facilities, a task to be carried out by experts from the six countries, the sources said.

North Korea, which tested a nuclear device last year, has shut down and sealed its Yongbyon atomic plant in return for energy aid and moves towards bringing it out of diplomatic isolation, first steps in the February agreement.

North Korea's request to be removed from a U.S. terrorism blacklist and the ambit of the U.S. Trading With the Enemy Act is also mentioned in the document, but without a time-frame for dealing with the issue, the diplomatic sources said.

"North Korea demanded the joint document stipulate specifically when the United States will remove it from the list," one of the sources said. "But the U.S. side rejected it."

In return for disabling and declaring its nuclear facilities, the agreement entitles North Korea to receiving energy aid equivalent to 950,000 tonnes of heavy fuel oil, the sources said.

Wu Dawei, the head of the Chinese delegation, said on Sunday the six-party talks would go into "recess" for two days but that after that the document should be made public.

U.S. envoy Christopher Hill said on Sunday the delegates were close to agreeing what "disabling" North Korean nuclear facilities meant, and the joint statement was full of detail.

But Japanese government officials said they could find the document not fully acceptable.

"This is not something we can easily say 'OK' to after going through it quickly," Vice Foreign Minister Shotaro Yachi told reporters.

On Friday, U.S. President George W. Bush authorised $25 million in aid, including up to 50,000 tonnes of heavy fuel oil, for North Korea as a reward for Pyongyang's commitment to disabling its nuclear facilities.