The leaders of China, Japan and South Korea on Saturday pledged to work together for an "early resumption" of talks on ending North Korea's nuclear programmes and vowed to deepen regional cooperation.

The leaders also said they would work together to ensure the success of global climate talks in Copenhagen later this year and promote the development of clean energy technologies.

The meeting between Chinese Premier Wen Jiabao, Japanese Prime Minister Yukio Hatoyama and South Korean President Lee Myung-Bak was only the second to bring the regional leaders together, after one in Japan last year.

"We will remain committed to dialogue and consultation and continue to work through peaceful means to pursue the denuclearisation of the Korean peninsula," the leaders said in a joint statement after the morning summit.

"We will make joint efforts with other parties for an early resumption of the six-party talks, so as to safeguard peace and stability in Northeast Asia, and thereby to build an Asia of peace, harmony, openness and prosperity."

North Korea said Monday during a visit by Wen that it was willing to return to six-party nuclear disarmament talks -- but only if it first was granted direct negotiations with the United States.

Washington has said it would agree to bilateral talks within the six-party framework, but that the goal must be a complete end to Pyongyang's nuclear weapons drive.

"We are faced with an opportunity, but this opportunity may slip by. The key is what we do. We need to seize the opportunity and make the most of it," Wen told a joint press conference.

"On the issue of the six-party talks, the DPRK side showed flexibility," he added, noting that Pyongyang "not only hopes to improve its relations with the US, but also to improve relations with Japan and South Korea".

The six-way negotiations are hosted by China, a close ally of North Korea, and also include South Korea, the United States, Russia and Japan.

Hatoyama said: "Premier Wen informed me that North Korea was willing to resume dialogue with Japan. I would like to trust these words."

South Korea's Yonhap news agency reported on Friday that a key North Korean diplomat was likely to visit the United States later this month, which could provide a rare opportunity for face-to-face talks with US officials.

Lee said he had presented what he describes as a "grand bargain" for North Korea's nuclear disarmament -- massive aid and diplomatic and security guarantees in return for a firm commitment to total denuclearisation.

"We agreed that it's important that the three countries cooperate on this issue," the South Korean president said.

Hatoyama backed Lee's approach while in Seoul on Friday, saying: "We should not provide economic aid unless the North signals a specific action or willingness comprehensively to (end) nuclear and missile development."

The Japanese and South Korean leaders called for a "fundamental change" in North Korea's attitude to end the nuclear standoff, and said sanctions should stay in force until then.

The three leaders also committed to expand their cooperation "in the spirit of facing history squarely and advancing towards the future".

Hatoyama, who took office last month, is looking to erase the distrust and frequent animosity that marked Tokyo's relations with its neighbours under the previous Liberal Democrat leadership.

Chinese State Councilor Dai Bingguo said Friday after meeting with Japanese Foreign Minister Katsuya Okada that relations between Beijing and Tokyo were off to a "good start" under Hatoyama, state media reported.

On climate change, the trio said they would "work closely together... to contribute to the successful achievement of the Copenhagen conference" -- while maintaining that countries bore "common but differentiated responsibilities".

More than 190 countries will converge in the Danish capital to try to hammer out a treaty to tackle global warming that will succeed the Kyoto Protocol, which expires in 2012.