WASHINGTON, April 12 — Abdul Qadeer Khan, the Pakistani scientist who sold nuclear technology around the world, has told his interrogators that during a trip to North Korea five years ago he was taken to a secret underground nuclear plant and shown what he described as three nuclear devices, according to Asian and American officials who have been briefed by the Pakistanis.

If Dr. Khan's report is true, it would be the first time that any foreigner has reported inspecting an actual North Korean nuclear weapon. Past C.I.A. assessments of North Korea's nuclear capacity have been based on estimates of how much plutonium it could produce and assessments of its technical capability to turn that plutonium into weapons.

Dr. Khan, known as the father of the Pakistani bomb, said he was allowed to inspect the weapons briefly, according to the account that Pakistan has begun to provide in classified briefings to nations within reach of North Korea's missiles. American intelligence officials caution that they cannot say whether Dr. Khan had the time, expertise or equipment to verify the claims. But they note that the number of plutonium weapons roughly accords with previous C.I.A. estimates that North Korea had one or two weapons and the ability to produce more...

...American officials have known about the Pakistani reports for at least three or four weeks, Asian and American officials say. But they have kept them quiet, and President Bush has not mentioned the country in public for weeks. Many Democrats say they believe that Mr. Bush is trying to play down the issue in an election year, especially because North Korea may be making more bombs as talks drag on.

Mr. Bush's aides say that they are making progress, and that there is no use publicly denouncing North Korea while diplomacy continues. If the country already has a few nuclear weapons, they say, a few more would not make a strategic difference.

"It's an untenable argument," said Samuel R. Berger, President Bill Clinton's national security adviser. "There's a difference between two or three and eight and it's called the market in weapons for global terrorists."