WASHINGTON -- North Korea has told the United States it has a secret nuclear weapons program in violation of an agreement signed with the Clinton administration, a senior administration official said Wednesday night.

North Korea also told U.S. diplomats it no longer beholden to the anti-nuclear agreement, said the official who spoke on condition of anonymity.

The disclosure, which stunned senior administration officials, is certain to chill U.S.-North Korean relations. President Bush had labeled the country part of the "axis of evil" - along with Iraq and Iran - but hopes were raised that the reclusive nation wanted to build international ties when Bush sent Assistant Secretary of State James Kelly to Pyongyang for security talks.

Kelly visited North Korea on Oct. 3-5 and demanded that the communist state address global concerns about its nuclear and other weapons programs.

In response, the Pyongyang government accused Bush's special envoy of making "threatening remarks." The United States refused all comment on the discussions,

Under a 1994 agreement with the United States, North Korea promised to give up its nuclear weapons program, and it promised to allow inspections to verify that it did not have the material needed to construct such weapons.

But it has yet to allow the inspections, drawing criticism from the Bush administration.

The source said Kelly also raised with North Korea evidence that North Korea may have a uranimum-enrichment program. The program, which the United States believes would only be used to develop a nuclear bomb, began under the Clinton administration, according to the official.

Surprisingly, North Korea confirmed the allegation.

The administration has not decided how to respond. "We're going to keep talking," the official said.

After months of tension with South Korea, the North resumed high-level talks in August that restarted stalled reconciliation efforts on the Korean peninsula - divided by the most heavily armed border in the world.

The Koreas were divided after World War II and remained that way at the end of the inconclusive Korean War from 1950-53. About 37,000 U.S. troops are stationed in South Korea as a deterrent against the North.

© 2002 The Associated Press