Beijing  - The leaders of China, Japan and South Korea agreed Saturday to cooperate to ensure the success of upcoming global talks on climate change in Copenhagen and to make "unremitting efforts toward sustainable development."

The leaders agreed to "work closely together ... to contribute to the successful achievement of the Copenhagen conference," according to a joint statement issued after talks among Chinese Premier Wen Jiabao, South Korean President Lee Myung Bak and Japanese Prime Minister Yukio Hatoyama.

International leaders plan to meet in Copenhagen December 7-18 to try to reach an agreement that would replace the Kyoto Protocol and regulate carbon emissions, which cause global warming. The current protocol expires in 2012.

The three nations said they wanted to establish an "effective post-2012 international cooperation framework on climate change ... in particular common but differentiated responsibilities."

China has long argued that developed countries have generated the largest amounts of greenhouse gases and should bear a greater burden in reducing them, while allowing developing nations to use economic development to raise their standards of living and reduce poverty.

Saturday's joint statement also committed China, Japan and South Korea to "work hard to develop green economy, promote balance between economic growth and social development, and contribute to the realization of sustainable development."

They promised joint efforts to promote "resource-conserving and environment-friendly" industrial structures, growth and consumption.

The three nations would also "work closely together and spearhead cooperative efforts in international frameworks for energy cooperation, aiming to promote sustainable development through deployment of clean energy and improvement of energy efficiency," the statement said.

In a separate statement, Wen, Lee and Hatoyama agreed to work together to persuade North Korea to resume talks on ending its nuclear weapons programme. (dpa)