South Korea's main opposition party leader called on the United States Tuesday to help resume the long-stalled six-party talks on North Korea's nuclear programs, saying he hopes to see the U.S. contribute to easing tensions on the Korean Peninsula.

Rep. Kim Han-gil, the chief of the main opposition Democratic Party (DP), made the remarks in a meeting with U.S. Ambassador to Seoul Sung Kim. The meeting came a day after Seoul spurned Pyongyang's call for a resumption of the six-nation talks, demanding that the communist nation prove by action that it is willing to denuclearize.

"It appears that the U.S. and South Korean governments are showing a cool response (to the North's call for talks), based on questions about North Korea's sincerity," the DP chief said. "The U.S. first started the six-party talks in order to denuclearize North Korea ... but I get the impression that the order has now changed when it says that denuclearization is a pre-condition for the talks to reopen."

The six-party forum, which began in 2003, has been suspended since the last session in late 2008.

The talks involve the two Koreas, the United States, China, Japan and Russia, and aim to dismantle North Korea's nuclear weapons program in exchange for economic and political aid.

North Korea quit the forum in a dispute over how to verify steps it was supposed to take to disarm. The North has since conducted its third nuclear test and declared that its nuclear programs are not negotiable.

"It is our desperate wish to see tensions eased on the Korean Peninsula," Rep. Kim said. "I hope the United States will play a role."

The ambassador stressed his country's resolve to denuclearize the Korean Peninsula jointly with the South, but voiced reservations about immediately resuming the six-nation forum.

The U.S. is open to dialogue with the North, but the communist country must first demonstrate its willingness to abandon its nuclear programs, he said. (Yonhap News)