BEIJING : US envoy Christopher Hill left Beijing late Saturday after a visit lasting just a few hours amid efforts to salvage a North Korean nuclear disarmament deal, a US embassy spokesman said.

Hill, who was in discussions this week in North Korea on the faltering deal to halt the communist state's nuclear ambitions, is heading to Washington via Tokyo, the spokesman said.

In Beijing, he briefed Chinese officials, including top nuclear negotiator Wu Dawei, as well as Sergey Razov, Russia's ambassador to China, on the visit to North Korea, the spokesman added.

China, Russia and the United States are members of six-nation talks aimed at halting the North's nuclear programme, along with the two Koreas and Japan.

Hill Friday described as "very substantive" the talks during his two-day visit to Pyongyang, but gave no further details.

He had arrived in North Korea on Wednesday, at the invitation of the communist regime, in an attempt to save a six-party nuclear disarmament deal signed in 2007.

The North shut down its Yongbyon nuclear complex in July last year and began disabling it in November. And in June it handed over a declaration of nuclear activities to China.

But now the North is angry that the US failed to respond by removing it from a terrorism blacklist, as required under the accord. It says it will soon begin work to restart a plutonium reprocessing plant, which could produce more bomb-making material from spent fuel rods.

Before delisting occurs, the US demands that the North agree on inspection procedures to ensure it is telling the truth in its declaration.

On Friday the State Department said North Korea was moving to restart its nuclear programme.

- AFP /ls