"China and United States will work together to collaborate through enhanced policy dialogue, including the sharing of information regarding their respective post-2020 plans to limit greenhouse gas emissions," said a US-China joint statement issued at the end of US Secretary of State John Kerry’s Beijing visit.

The two sides ‘commit to devote significant effort and resources to secure concrete results’ by the sixth US-China Strategic and Economic Dialogue later this year, the statement added.

"Both sides reaffirm their commitment to contribute significantly to successful 2015 global efforts to meet this challenge," the statement said.

International talks to try to agree on a successor to the 1997 Kyoto Protocol, the first and only international agreement to tackle climate change, are due to be held in Paris next year. United States never ratified the Kyoto deal.

A new global pact might include pledges on curbing greenhouse gas emissions and measures to enable the poorest nations to adapt better to climate change. Kerry welcomed Chinese cooperation.

“This is a unique, cooperative effort between China and United States and we have hopes that it will help to set an example for global leadership and global seriousness on the issue of next year's climate negotiation," Kerry told reporters before departing for Jakarta.

"China and United States will put an extra effort into exchanging information and discussing policies that will help both of us to be able to develop and lead on the standards that need to be announced next year for the global climate change agreement," Kerry said.

The Intergovernmental Panel on Climate Change said in a report last September they were more convinced than ever that humans are the main culprits for global warming, and predicted the impact from greenhouse gas emissions could linger for centuries.

UN Secretary-General Ban Ki-moon said the study was a call for governments, many of which have been focused on spurring weak economies rather than fighting climate change, to work to reach a planned U.N. accord in 2015 to combat global warming.

Ban is seeking to re-energize the global climate change debate and boost the UN's role. He has appointed former New York City Mayor Michel Bloomberg, former Ghana president John Kufuor and former Norwegian Prime Minister Jens Stoltenberg as special envoys on climate change.