WASHINGTON : The United States launched a new diplomatic drive on Tuesday to secure a long-awaited deal to scrap North Korea's atomic arms by sending key envoys this week to Pyongyang and nearby Asian capitals.

The State Department said Korea expert Sung Kim was due in Pyongyang on Thursday while Deputy Secretary of State John Negroponte will leave on Wednesday for Tokyo, Seoul and Beijing.

The visits which it said are part of efforts to obtain a full declaration from North Korea on its nuclear programs come two weeks after Washington alleged that the North had helped Syria build a reactor for a weapons project.

The State Department was circumspect when asked whether a deal was likely before the end of the month.

"We'd hope they produce a declaration in a short span of time. We are way past what was expected," spokesman Sean McCormack told reporters. "As we've said, the ball is in their court. We'll see if they meet their obligations."

A senior South Korean official told reporters in Seoul last Friday that North Korea is expected to submit the declaration within one week or two to China, which hosts the six-party nuclear talks, and finally break the deadlock.

The North, which staged a nuclear test in October 2006, is disabling its plutonium-producing reactor and other plants under a deal reached last year with the United States, China, Japan, Russia and South Korea.

But disputes over the declaration due on December 31 have blocked the start of the final phase of the disarmament process - the dismantling of the plants and the handover of all material.

In return for total denuclearisation, the impoverished Stalinist state would receive energy aid, a lifting of US sanctions, the establishment of diplomatic relations with Washington and a formal peace treaty.

In addition to the declared plutonium bomb-making operation, the US said the declaration must clear up suspicions about an alleged secret uranium enrichment programme and about suspected involvement in building a nuclear plant in Syria.

The North denies both activities. Under a reported deal, it will merely "acknowledge" US concerns about the two issues in a confidential separate document to Washington.

McCormack told reporters that Kim's talks in Pyongyang, which he believed will take place on Thursday, will follow up those he had when he last visited the North in April to discuss the promised declaration.

He added that Negroponte, the State Department's number two, will visit Tokyo, Seoul and Beijing as part of the six-party negotiations.

He said "I'm sure he will touch on that (nuclear issue) as part of his discussions," but added Negroponte will also discuss other "significant bilateral regional issues" on each stop of a tour ending May 12.

State Department press officer Nancy Beck confirmed that the visits come as "a team of US experts is currently in Pyongyang to continue discussions" on providing US food aid to help it deal with "significant food shortages."

But she told reporters the discussions "remain inconclusive."

The provision of food aid depends on the level of need, supply "and our view of other needs that might exist, and our ability to ensure aid is reliably reaching the people in need," Beck said.

South Korean foreign ministry spokesman Moon Tae-Young said "North Korea is known to be suffering difficulties because of a poor harvest following last year's floods and a recent hike in grain prices."

The Peterson Institute said food prices in the hardline communist state have almost tripled in the last year. "Anecdotal reports describe a breakdown in institutions and increasingly repressive internal behaviour," it said. - AFP/de