A former U.S. ambassador to South Korea says that North Korea views an international accord requiring it to dismantle its nuclear weapons program is "hanging by a thread." The comments by Donald Gregg appear to contradict assertions from the United States that Pyongyang is still attempting to build nuclear arms.

During his visit, former ambassador Donald Gregg asked North Korea's Deputy Foreign Minister Kang Sok Ju about the 1994 Agreed Framework. The agreement with the United States required Pyongyang to scrap an earlier nuclear program.

"Kang's response was 'It is hanging by a thread,'" Ambassador Gregg said. "Meaning it was in a very tenuous state but that the North Koreans were still supporting it."

However, North Korea a few weeks ago declared the 1994 accord void because of delays in building two light-water reactors. It is to receive the reactors in return for dismantling the earlier program, which could have generated plutonium for bombs.

Last month, the United States reported that Pyongyang had admitted to enriching uranium for use in nuclear weapons.

At a press conference in Seoul Wednesday, Mr. Gregg says North Korean officials were vague about the matter.

"The North Koreans said they had adopted a NCND, neither confirm nor deny, policy toward the highly enriched uranium issue," he said. "Though some comments we heard were very close to admissions that they had such a program under way."

The United States, South Korea and Japan demand that North Korea swiftly and visibly dismantle its nuclear weapons program.

North Korea argues it has a right to develop nuclear weapons as protection against what it describes as a hostile United States. It demands that Washington sign a non-aggression pact and guarantee the North's sovereignty to resolve the dispute.

Ambassador Gregg said he detected some possible flexibility in Pyongyang's stance.

"There seemed to be a movement from their assertion that the United States had to take a first step to break the current impasse, to an assertion that simultaneous actions should be taken to resolve current issues," he said. "And this we regarded as possibly a step toward progress."

Mr. Gregg, a former U.S. ambassador to South Korea, says he spent four days in Pyongyong as a private citizen.