Gates refused to confirm the veracity of leaked intelligence reports suggesting that North Korea may be helping Syria build a nuclear weapons facility.

"But all I will say is we are watching the North Koreans very carefully. We watch the Syrians very carefully," he said on Fox News.

"If such an activity were taking place, it would be a matter of great concern because the president has put down a very strong marker with the North Koreans about further proliferation efforts and obviously any effort by the Syrians to pursue weapons of mass destruction would be a concern.

"I think it would be a real problem," Gates said.

A senior North Korean diplomat has dismissed the media reports that the Stalinist state may be helping Syria on the nuclear front, South Korea's Yonhap news agency said Sunday.

"They often say things that are groundless," Kim Myong-Gil, the North's deputy UN mission chief, told Yonhap in the first official response to last week's reports about alleged cooperation between Pyongyang and Damascus.

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NKorean envoy dismisses Syria nuclear links
A senior North Korean diplomat has dismissed media reports that the communist state may be helping Syria build a nuclear facility, South Korea's Yonhap news agency said Sunday.

"They often say things that are groundless," Kim Myong-Gil, the North's deputy UN mission chief, told Yonhap in the first official response to last week's reports about alleged cooperation between Pyongyang and Damascus.

When asked to elaborate, the North Korean diplomat hung up the telephone, Yonhap said.

Both the New York Times and Washington Post reported, citing unnamed sources, that North Korea may be helping US arch-rival Syria build a nuclear weapons facility.

The Washington Post quoted unnamed intelligence sources as saying Israeli secret service had relayed the information to the US government, which it described as "dramatic."

The reports came ahead of this week's new round of six-party talks among the two Koreas, the United States, China, Japan and Russia, amid hopes that Pyongyang will declare and disable its atomic programmes by year's end.

A US-led team of nuclear experts said they had "very positive" talks with North Korean officials on detailing a plan to disable the communist state's nuclear facilities during a trip to Pyongyang last week.

The team is scheduled to deliver a report at the six-nation talks due to open in Beijing on Wednesday.

Washington for decades has accused North Korea, which carried out a nuclear weapons test in October 2006, of weapons proliferation. US officials have charged Syria with bankrolling terrorism groups in the Middle East.