Top nuclear negotiators for China, the United States and North Korea met Tuesday as part of a renewed diplomatic push to resume stalled six-nation talks on North Korea's atomic weapons program.

China's Vice Foreign Minister Wu Dawei, US Assistant Secretary of State Christopher Hill and North Korean Vice Foreign Minister Kim Kye Gwan met after Kim arrived earlier Tuesday from Pyongyang, Chinese Foreign Ministry spokeswoman Jiang Yu said.

She said the talks were ongoing and did not give any details.

China hopes that "relevant parties can have an in-depth exchange of ideas in order to promote the early resumption of talks," Jiang said at a regular briefing.

Kim's trip to Beijing - a rare overseas visit - and the presence of other negotiators added to prospects of compromises to give new life to the talks, which have been at an impasse for more than a year.

Officials have yet to determine an exact date for the next round of negotiations, which also involve Russia.

Kim said the timing "depends on the United States."

"There are too many outstanding issues" and both parties should narrow their differences, Kim told reporters on arrival at the airport.

"I said on October 31 that we can enter the talks at any time," he said. "I said that because we can do that from a dignified position as we have taken defensive measures through our nuclear test to counter sanctions and pressure against us."

An unannounced meeting between Hill and Kim last month in Beijing led to Pyongyang agreeing to return to the arms negotiations amid heightened tensions after its first nuclear test on October 9.

"The issue for us is to make sure we are extremely well-planned and ready for the six-party talks, which we do anticipate will get going at some point very soon," Hill said when he arrived on Monday.

Hill met separately with South Korea's nuclear envoy, Chun Yung-woo, and Wu Tuesday morning, said Susan Stevenson, the spokeswoman for the US Embassy in Beijing. She did not have any details on the talks.

Japan's representative Kenichiro Sasae told Japanese reporters that he had also held bilateral talks with Wu and Hill.

North Korea agreed in September 2005 to abandon its nuclear program in exchange for security guarantees and aid. But Washington imposed financial sanctions against a Macau-based bank on suspicions it was laundering counterfeit money for the North Koreans. Angered by the move, Pyongyang withdrew from the talks two months later.

Chun has said getting preparations right for progress at the talks was more important than setting a date for restarting the negotiations.

"We will mainly focus on the procedure of the talks as it is essential to accomplish substantial progress rather than talking just for the sake of talking," he told reporters after arriving in Beijing on Monday.