Seoul, South Korea ? North Korea is willing to discuss allegations it has a uranium-based nuclear weapons program, a media report said Thursday, as Washington warned progress at six-nation talks will hinge on the North’s willingness to abandon its atomic ambitions.

The disputed uranium program is a key stumbling block in next week’s nuclear talks in Beijing involving the United States, the two Koreas, China, Russia and Japan.

North Korea has denied a U.S. contention that it had a secret uranium program in addition to its program using plutonium. But the communist government conveyed to a “third country” its willingness to discuss the matter with Washington, South Korea’s Yonhap news agency said.

In Tokyo, U.S. Undersecretary of State John Bolton said North Korea’s alleged uranium-based and plutonium programs should both be up for discussion.

“To get all the issues on the table … is going to be a very important diplomatic aspect of the talks,” he told reporters at the U.S. Embassy in Tokyo.

Bolton added that the success or failure of the talks would hinge on whether North Korea expressed willingness to give up its nuclear weapons programs. Earlier, he warned that the dispute over the highly enriched uranium, or HEU, program could derail chances of a peaceful resolution.

The six-nation talks begin Wednesday. A first round of meetings in August made little progress.

China appealed Thursday to governments taking part in the talks to remain diplomatic, saying “a solution to the nuclear issue can only be achieved through dialogue and political negotiations.”

“It’s very important to stick to that consensus,” Foreign Ministry spokesman Zhang Qiyue said.

Questions about North Korea’s nuclear capabilities are expected to overshadow the talks.

Gen. Leon J. LaPorte, commander of U.S. forces in South Korea, described the North as a world threat.

“What would happen if North Korea sold nuclear technology or weapons-grade plutonium or uranium to a terrorist organization that could take that any place in the world and detonate a nuclear weapon?” he said Thursday.

But LaPorte said U.S. forces were planning no pre-emptive strike and that the nuclear standoff with Pyongyang must be resolved diplomatically.

Washington claims Pyongyang admitted to running an HEU program — in addition to the plutonium program — when U.S. officials visited the communist country in October 2002. North Korea accused the United States of making the claim to flare the nuclear crisis.