The United States has proposed a meeting of North Korea's neighbors and other regional powers on the sidelines of the upcoming meeting of U.N. General Assembly, South Korea's top nuclear envoy said Monday.

Such a meeting could put more pressure on North Korea as the communist state refuses to rejoin the six-party talks aimed at ending its pursuit of nuclear weapons.

The move also comes amid concerns the North may be preparing to test a nuclear bomb to further heighten tensions created by its test-firing of a series of missiles in July.

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Chun Yung-woo, the chief South Korea nuclear negotiator, said the U.S.-proposed session would be like one that 10 countries held in Kuala Lumpur, Malaysia, on the sidelines of an annual security forum in July to discuss North Korea's missile and nuclear programs.

The 10 countries consisted of all parties to the six-nation nuclear talks except North Korea — China, Japan, South Korea, Russia and the U.S. — plus Australia, Malaysia, Indonesia, Canada and New Zealand.

"For now, the U.S. is thinking of holding a meeting similar to the one held in Kuala Lumpur," Chun said after talks with his U.S. counterpart, Assistant Secretary of State Christopher Hill. "But not all of the related countries have responded."

Hill said his discussion with Chun included "the possibilities of having various talks" now that the six-party talks have been deadlocked for almost a year.

"We don't want a situation where the North Koreans, who are boycotting the talks, can also veto anyone else from talking," he said. "So we had some discussion about that."

But the U.S. diplomat stressed that such a session wouldn't weaken the six-party talks and said Washington is committed to the dialogue process.

North Korea has refused to attend the six-party talks since last year in anger at U.S. efforts to choke off the North's access to international banking over its alleged currency counterfeiting and other wrongdoing.

"Sometimes, small countries can make terrible mistakes. That's really what they are doing," Hill said upon arrival in South Korea. "They are causing a lot of difficulties and really disturbing harmony in the whole region."

Pyongyang has demanded direct talks with the United States, but Washington has said it would only meet the North along with other countries. Hill repeated the U.S. would talk to North Korean officials on the sidelines of the six-party talks "as many times as they would like."

Hill also said the United States is prepared to discuss the financial issue with North Korea if it comes back to the negotiating table and moves toward implementing a September 2005 agreement where Pyongyang promised to abandon its nuclear program in exchange for aid and security guarantees.

"If [North Korea] wants to come forward and implement the September agreement, I have no doubt we can work out some of these financial issues," Hill said. "The problem is they don't seem to want to implement the agreement. That's the basic problem."

Hill arrived in Seoul earlier in the day on the final leg of an Asian tour that also took him to Japan and China. He also met with South Korean Unification Minister Lee Jong-seok and discussed the possibility of a nuclear weapons test by the North.

Concerns have persisted in recent weeks that North Korea may be preparing to conduct its first known nuclear test following reports last month of suspicious activity at a suspected North Korean underground nuclear testing site. South Korea's main spy agency has said the communist regime could test a nuclear device at any time.

On Monday, South Korean Defense Minister Yoon Kwang-ung told a parliamentary meeting that a nuclear test by the North remains a possibility but did not elaborate, according to his ministry.

North Korea claims to have nuclear weapons but has not performed any known tests to verify it has successfully built them. Many experts believe the North has enough radioactive material to build at least a half-dozen or more nuclear weapons.