Less than three weeks after the reclusive Stalinist regime agreed to freeze its key nuclear facility, US Assistant Secretary of State Christopher Hill met with his North Korean counterpart Kim Kye-gwan Monday before hosting his visitor to dinner at New York's grand Waldorf Astoria Hotel.

It was the highest level meeting held in the United States between the two nuclear rivals since October 2000.

Hill said the meeting, which would continue on Tuesday, was aimed at setting the pace for bilateral relations, including North Korea's possible removal from a US list of state terrorism sponsors.

"These were some preliminary discussions," Hill told reporters after the four-hour talks late Monday.

He told The New York Times earlier that the two-day meeting was aimed at crafting an agenda "to work on our bilateral relationship," including criteria for North Korea to be removed from the state-sponsor-of-terrorism list and for scrapping longstanding US trade sanctions against the hardline communist regime.

He also said he would be "pressing for disclosure" of all of the nuclear programs of North Korea, whose defiant atomic weapons test in October last year drew unprecedented UN sanctions.

Kim, often guarded with his comments, said he was optimistic about the talks.

"I think everything will go well," he told South Korea's news agency Yonhap.

Kim also reportedly told his South Korean counterpart Chun Yung-Woo in separate talks in New York that North Korea was willing to shut down its nuclear plants in an "irreversible" manner.

US officials say the meeting here is just a small step toward improving relations with the reclusive Asian Marxist state that US President George W. Bush in 2002 famously included as part of his "axis of evil."

But analysts describe it as a breakthrough in efforts to end more than 50 years of feuding since the United States led an international force against the North in the 1950-1953 Korean War, which has never officially ended.

The bilateral talks also meet a long-standing condition set by North Korea for abandoning its nuclear ambitions, and are aimed at smoothing implementation of a landmark agreement reached with Pyongyang on February 13.

Under the accord, North Korea agreed to close and seal its Yongbyon nuclear facility -- long suspected to be the center of its nuclear program -- within 60 days and admit UN nuclear inspectors in return for 50,000 tonnes of heavy fuel oil.

Further steps to disable nuclear facilities would be rewarded with up to 950,000 tonnes of heavy oil or other aid, according to the agreement reached with North Korea by Washington and its negotiating partners China, Russia, Japan and South Korea.

Kim and other North Korean officials earlier Monday held talks with US officials and dignitaries, including National Security Council director for Asian affairs Victor Cha and former US secretaries of state Henry Kissinger and Madeleine Albright, at the New York-based Korea Society.

They discussed "a range of bilateral issues and concerns," including prospects for normalization of relations, a statement said.

"Participants on both sides welcomed the opportunity to examine in detail matters of mutual concern which for some time had not been addressed bilaterally," it said.

Albright made a landmark visit to Pyongyang in 2000 that eased tensions until Bush took office a year later. In the wake of the September 11, 2001, attacks on New York and Washington, Bush in January 2002 included North Korea in an "axis of evil" alongside Iran and Iraq under the late dictator Saddam Hussein.

Hill on Tuesday is scheduled to address a forum of the Japan Society and brief the media at the end of the bilateral talks.

The New York talks come a week before Mohamed ElBaradei, head of the UN International Atomic Energy Agency, is to travel to North Korea to discuss how to monitor its promised dismantling of nuclear facilities.

They also coincide with a burgeoning controversy in Washington over the reliability of US intelligence on North Korea and whether Washington overstated Pyongyang's efforts to enrich uranium in 2002.

US intelligence officials defended their work over the weekend but said that while they had high confidence Pyongyang tried to enrich uranium in 2002, they had only moderate confidence it was still pursuing the goal.

US Deputy Secretary of State John Negroponte, on an Asian tour focused on getting North Korea to abide by its commitment, said Tuesday he was certain Pyongyang had a secret uranium enrichment program to make bombs but stopped short of saying whether it still exists.

"I have no doubt that North Korea has had a highly enriched uranium program, and that has been and continues to be the judgment of our intelligence community," Negroponte said at a news conference in Seoul.

"We would expect that when North Korea makes its declaration of nuclear facilities, that that would be one of the issues addressed in North Korea's declaration."