"Even though the Americans have been counting this [report] as progress, some critics say the report is not a full diclosure of what the North Koreans have been up to in the past few years.

"Others say the six-party talks are a diplomatic process that will last for some time and any sort of development of this kind should be welcomed as a positive move."

Nuclear pledge

Pyongyang has said it would destroy an old cooling tower at its main Yongbyon nuclear complex on Friday, in a public display of its commitment to its obligations under the disarmament deal.

The handover of the North Korean declaration would be a significant step in the implementation of a six-party nuclear disarmament pact signed early last year.

China hosted talks that secured the deal offering North Korea diplomatic and economic incentives to disable its main nuclear facility and declare all related programmes.

Officials involved in the talks said Pyongyang itself set Thursday as the deadline to deliver the report to Beijing.

The US' removal of North Korea from their terrorist sponsor list could ease international trade and financial restrictions, as well as improving ties between Pyongyang and Washington.

Japan has expressed unease over the North being taken off the US blacklist before the issue of its citizens kidnapped by Pyongyang is resolved.

Tokyo is expected to raise the issue with Condoleezza Rice, the US secretary of state, when she attends a G8 foreign ministers' meeting in Japan on Thursday.