Talks aimed at reining in North Korea's nuclear programmes ended on Sunday to allow delegates to return to their home countries to discuss a "nuts and bolts" joint statement with their governments, the U.S. envoy said.

Under an accord reached in February, North Korea must disable its atomic facilities and make a complete declaration of all its nuclear programmes. In return, the impoverished communist state will receive a massive injection of fuel aid.

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

"Several of us felt we should take it back (to home countries) because of the details, but assuming we go forward with this, it really lays out an entire roadmap through the end of the year," he told reporters before leaving for Washington.

"Frankly, of all the six-party meetings, this was the least stressful in terms of coming up with common positions ... We are really into the nuts and bolts now of implementing denuclearization."

Chinese delegation head Wu Dawei said talks would go into "recess" for two days but that after that the document should be made public.

Hill said Washington agreed to most of it but because of the detail he "needed to walk people through it".

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.

The six-party forum, hosted by China and involving the two Koreas, the United States, Japan and Russia, has been pressing Pyongyang to disable its atomic facilities and make a complete declaration of related programmes.

On Friday, U.S. President George W. Bush authorized $25 million in aid for the North, which would provide up to 50,000 tonnes of heavy fuel oil, as a reward for Pyongyang's commitment to disable its nuclear facilities by the end of the year.

China and South Korea have delivered initial fuel shipments and Russia is expected to do so too. But Japan has indicated it will not participate unless North Korea addresses the issue of Japanese citizens the North abducted in the 1970s and 1980s.

(Additional reporting by Kim Soyoung in Seoul and Kiyoshi Takenaka in Tokyo)