SEOUL, April 1, 2008 (AFP) - US negotiator Christopher Hill was to arrive in South Korea later Tuesday to discuss ways to restart stalled nuclear talks with North Korea, amid signs of growing impatience by both sides.

Seoul's Chosun Ilbo newspaper said Hill has already confronted Pyongyang with alleged evidence of its nuclear links to Syria -- one of the two key issues holding up progress in a landmark denuclearisation deal.

Chosun said Hill presented a list of North Korean officials and engineers involved in the technology transfer during a recent bilateral meeting with his North Korean counterpart Kim Kye-Gwan.

The newspaper, quoting a diplomatic source, said Kim denied any knowledge of the list said to have been obtained through intelligence networks.

Chosun did not say where the confrontation took place. The two envoys had bilateral talks in Bejing in February and in Geneva last month, with no tangible progress announced.

The South's foreign ministry declined comment.

The six-nation deal, involving the United States, China, the two Koreas, Japan and Russa, is stalled over a promised declaration from the North of all its past nuclear activities.

The North says it submitted the declaration in November. But the United States says it has not fully accounted for a suspected secret uranium enrichment weapons programme and for alleged nuclear proliferation to Syria.

Last September Israel launched an air strike in the Arab state, which Western media reports said targeted a nuclear plant developed with North Korea.

As part of the six-party deal the North is disabling atomic plants which produce bomb-making plutonium. It categorically denies any separate secret uranium programme or any profileration, and says it could slow down the disablement if the stalemate continues.

The US and South Korea also pushed for progress at a Washington meeting last week between Secretary of State Condoleezza Rice and visiting Foreign Minister Yu Myung-Hwan.

Yu told reporters that 'time and patience' are running out.

The US embassy said Hill will stay in South Korea until leaving for Indonesia Thursday. It had no comment on media speculation about a possible Hill-Kim Kye-Gwan meeting in a third country, but said the US envoy has no plan to visit China during this trip.

Hill will hold a dinner meeting with his counterpart Chun Yung-Woo Tuesday. On Wednesday he is scheduled to meet Vice Foreign Minister Kwon Jong-Rak and Deputy Foreign Minister Lee Yong-Joon.