North Korea said Wednesday it has reached agreement with the United States on its promised nuclear declaration, an issue that has blocked progress in a six-nation disarmament deal.

A foreign ministry spokesman quoted by state media said the two sides, during talks in Singapore Tuesday, also agreed on "political compensation" from Washington.

The North demands that the US start the process of removing it from a list of state sponsors of terrorism, in return for a declaration.

"As a result of the talks, a consensus was reached on the US measure to make political compensation and the nuclear declaration essential for winding up the implementation of the agreement," the unidentified spokesman was quoted by the communist state's Korean Central News Agency as saying.

US negotiator Christopher Hill said in Beijing Wednesday his talks with his counterpart Kim Kye-Gwan in Singapore had "definitely made progress" on the declaration.

"I don't want to suggest there has been any major breakthrough. But as the days go by, we'll be announcing some efforts to try to move ahead," Hill added.

The 2007 disarmament deal grants North Korea -- which tested an atomic weapon in 2006 -- energy aid and major diplomatic and security benefits in return for full denuclearisation.

The current phase required it to disable its main plutonium-producing plants and declare all nuclear activities by the end of last year.

The North says it submitted the declaration last November. The United States says it has not accounted for an alleged secret uranium enrichment programme or for alleged proliferation to Syria.

Media reports say there may have been a deal to address the uranium and proliferation concerns in a "confidential minute," while the official declaration would deal only with the acknowledged plutonium operation.

The North has always denied any secret uranium-based weapons programme and any proliferation efforts.

"The recent Singapore agreement fully proved the effectiveness" of direct talks with the United States, the spokesman said, adding it would watch that other members of the six-party forum kept their commitments.

The talks group the two Koreas, the US, host China, Japan and Russia. The North has complained about delays in delivering promised energy aid.