The North Korean envoy to international talks aimed at convincing his country to abandon its nuclear program said Tuesday that banning atomic weapons on the Korean Peninsula was the main issue at the negotiations. He promised his delegation would work toward that goal.

The talks Tuesday are the fourth such six-nation negotiations, which also include China, Japan, Russia, South Korea and the United States. They are reconvening after a 13-month boycott during which the North refused to attend, citing "hostile" U.S. policies.

"The fundamental thing is to make real progress in realizing the denuclearization of the Korean Peninsula," North Korean Vice Foreign Minister Kim Kye Gwan (search) said at the opening session of the talks in Beijing.

"This requires very firm political will and a strategic decision of the parties concerned that have interests in ending the threat of nuclear war," he said. "We are fully ready and prepared for that."

Pyongyang (search) agreed to return to the talks following a meeting earlier this month between Kim and the main U.S. envoy, Assistant Secretary of State Christopher Hill (search), who reassured North Korea that Washington recognized its sovereignty.

On Tuesday, Hill repeated his assurances.

"We view [North Korea's] sovereignty as a matter of fact. The United States has absolutely no intention to invade or attack" North Korea, Hill said in his opening remarks.

Unlike previous rounds, no end date has been set for the resumed negotiations. Hill said Tuesday his delegation would remain in Beijing "so long as we are making progress in these talks."

All three previous rounds — the last in June 2004— were limited to three days.

"We do not have the option of walking away from this problem," Hill said

"Nuclear weapons will not make [North Korea] more secure," Hill said. "And in fact, on the contrary, nuclear weapons on the Korean Peninsula will only increase tension in the region."

Neither the North Koreans or the Americans offered any new proposals or concessions in their opening comments. South Korea's envoy, Deputy Foreign Minister Song Min-soon, repeated his nation's offer of electricity aid to the North if it agrees to disarm.

The latest nuclear standoff with North Korea erupted in late 2002, when U.S. officials accused the communist nation of running a secret uranium enrichment program in violation of an earlier agreement between the two countries.

Since then, the North has pulled out of the Nuclear Nonproliferation Treaty and taken steps that would allow it to harvest more radioactive materials for atomic bombs. In February, the North publicly claimed it had nuclear weapons, but it has not performed any known tests that would confirm it can make them.

North Korea has demanded aid, a peace treaty with Washington and diplomatic relations in exchange for giving up nuclear development. It wants aid in exchange for freezing and then scrapping the program.

The United States says it will not offer concessions until the program is permanently dismantled.

The talks have been complicated by Japan's insistence on also settling the issue of Japanese citizens abducted by the North's spy agency.

The leader of Tokyo's delegation, Kenichiro Sasae, said Monday that Japan and the United States agreed to "cooperate closely" to address the abductions. His comments were broadcast on Japan's NHK television.

On Monday, South Korean officials pressed Japan not to let other issues obstruct progress on the nuclear dispute, according to a Seoul official.