Singapore - The top US and North Korean nuclear negotiators started talks Tuesday to try to break the deadlock over the communist country's atomic programme.

Christopher Hill, assistant US secretary of state for East Asian and Pacific affairs, and North Korean Vice Foreign Minister Kim Kye Gwan arrived separately at the US embassy in Singapore.

"What is important for us to try and achieve is to get back to having six-party meetings as soon as possible," Hill said earlier, referring to six-nation talks aimed at ending Pyongyang's nuclear programmes.

No time limit was set for the Singapore meeting. "It could end quickly or at night," said am embassy spokeswoman, stressing it was up to the participants.

Hill and Kim held separate talks Friday night with senior officials from Singapore's Foreign Affairs Ministry. Hill arrived from Indonesia and Kim from Beijing.

The six-party talks have been deadlocked since the end of last year over North Korea's declaration of its nuclear programmes, facilities and materials, which it was required to submit under a deal with the United States, China, South Korea, Japan and Russia.

Hill met with Kim in Geneva last month, but they were unable to break the impasse.

The United States has charged that the declaration North Korea submitted was incomplete and has been pressing Pyongyang to come clean on its alleged enrichment of uranium and suspicions that it has shared nuclear technology with other countries. Enriched uranium could be used to produce nuclear weapons.

Under a deal reached at the six-party talks in February last year, North Korea would receive energy and economic aid as well as diplomatic benefits in return for full denuclearization.

Hill was expected to give a press briefing following his talks and leave for Beijing Tuesday night.