PALO ALTO (California), Feb 23: Four years after Pakistan’s top nuclear scientist confessed to leaking weapons technology to N. Korea, the North Koreans have denied receiving any such help, an American researcher said.

The North Koreans dismissed the confessions from Pakistan, saying, “That’s your story,” researcher Siegfried Hecker said.

The North Koreans also told Hecker they had nothing to do with a suspected Syrian nuclear site destroyed by Israeli fighters in September, he said.

Media reports, some quoting unidentified US officials, have said the strike hit a nuclear installation linked to North Korea.

Hecker, a Stanford University professor and a former director of the Los Alamos National Laboratory, said he questioned North Korean officials on the two issues during a trip to that country from Feb 12-16. Hecker also visited the country’s Yongbyon nuclear facility on Feb 14.

Pyongyang’s past actions are sticking points in disarmament efforts under way now, because under recent agreements, North Korea is supposed to provide a full accounting -- a declaration -- of its nuclear programmes and activities.

Hecker has visited the North annually for the past five years, and last week’s trip was unofficial. Nevertheless, he pressed North Korean officials, whom he would not identify, on issues of concern to the United States, he said.

He told a small group of reporters on Wednesday that he had made plain that the issue of the Syrian site destroyed in September was “high on the list of American concerns.” And US officials are still awaiting North Korea’s account of nuclear ties to Pakistan following Islamabad’s acknowledgments years ago of the transfers, he said.

In early 2004, scientist Dr Abdul Qadeer Khan admitted that he had transferred nuclear weapons technology to Iran, North Korea and Libya.

Enriching uranium, a step toward producing nuclear fuel for weapons, requires centrifuge technology.

Hecker said he told the North Koreans that “one of the reasons the Americans want a full accounting is because of those statements.”

“When I bring up the Pakistan connection, they say, “That’s your story, we haven’t dealt with the Pakistanis on uranium enrichment,” Hecker said.

Asked whether the North Koreans meant they had never done so, Hecker said: “They’re talking about all times: They have not done this with the Pakistanis now or in the past, meaning, have not cooperated in uranium enrichment.

“Since I specifically posed the question in terms of having bought the uranium centrifuges, they said, ‘We have not, that’s your story.’”

As part of its push for a complete declaration from North Korea, the US is asking it to address its suspected uranium enrichment programme -- an issue that touched off a nuclear standoff in late 2002. North Korea denies ever having such a programme, and reiterated its denials to Hecker.

Earlier this week, Assistant Secretary of State Christopher Hill said North Korea’s declaration must cover both uranium enrichment and Pyongyang’s relations with Syria, to which it has been accused of providing nuclear assistance. Hecker said he believed it was possible there were North Korean connections to the site bombed in September, whose true purpose remains officially unknown. Damascus has denied having a secret atomic programme.

“If you look at potential connections, North Korea has the capabilities in the nuclear arena, so one at least has to consider that as a possibility,” Hecker said.

When he asked the North Korean officials about it, “their comment was, we don’t have anything to do with Syria in the nuclear arena.”

An October agreement forbids North Korea to export nuclear materials and technology in the future.

Asked whether the North Koreans had denied any involvement with the site bombed by the Israelis, Hecker said: “No, they were not that specific, but then I didn’t ask the questions in such a fashion to try to pin them down exactly to that site. I should add that I made it very clear that that’s the site I was talking about in terms of a Syrian connection.”—AP