Leaders remain split on specifying targets
World leaders meeting in Singapore have said it will not be possible to reach a climate change deal ahead of next month's UN conference in Denmark.
After a two-day Asia-Pacific summit, they vowed to work towards an "ambitious outcome" in Copenhagen.
But the group dropped a target to halve greenhouse gas emissions by 2050, which was outlined in an earlier draft.
Leaders also vowed to pursue a new strategy for growth after the world's worst economic crisis in decades.
They resolved to conclude the Doha round of global trade talks in 2010.
In a joint declaration issued at the end of their two-day annual summit, they said: "We firmly reject all forms of protectionism and reaffirm our commitment to keep markets open and refrain from raising new barriers to investment or to trade in goods and services."
They also agreed to keep stimulus spending in place until a recovery was seen.
But leaders have failed to agree a target for reducing greenhouse gas emissions at the Asia-Pacific Economic Co-operation (Apec) forum.
Officials said the leaders - including presidents Barack Obama of the US and Hu Jintao of China - now viewed the Copenhagen summit as a "staging post", and not an end point, in the search for a global deal to cut emissions of greenhouse gases.
"We... reaffirm our commitment to tackle the threat of climate change and work towards an ambitious outcome in Copenhagen," they said in the final declaration.
"Global action to reduce greenhouse gas emissions will need to be accompanied by measures, including financial assistance and technology transfer to developing economies for their adaptation to the adverse impact of climate change," the declaration said.
A Chinese official involved in the world climate talks said the 50% reduction target was "a very controversial issue in the world community" which could "disrupt the negotiation process".
US Deputy National Security Adviser Mike Froman said the leaders had reached the conclusion that "it was unrealistic to expect a full, internationally legally-binding agreement to be negotiated between now and when Copenhagen starts in 22 days".
1. Friday 13: Arrived in Japan
2. Saturday 14: Joined Apec summit in Singapore
3. Sunday 15: Had talks with Russia's President Medvedev before leaving for China
4. Tuesday 17: Summit in Beijing with Chinese President Hu Jintao
5. Wednesday 18: Ends tour in South Korea
This was unwelcome evidence that the gap between developing and developed nations, between rich and poor, East and West can sometimes be hard to bridge, says the BBC's Rachel Harvey in Singapore.
Mr Obama later met his Russian counterpart as the clock ticks for the world's two leading nuclear powers to strike a new arms reduction deal.
The deal is meant to replace the Strategic Arms Reduction Treaty (Start I), which expires on 5 December.
After the meeting, Russian President Dmitry Medvedev said he hoped that "as we agreed earlier... we can finalise the treaty by December".
The two leaders also said they were unhappy with the pace of talks over Iran's nuclear programme.
"We are running out of time with respect to that approach," Mr Obama said.
Mr Obama kicked off his week-long Asian tour in Japan on Saturday.
In Tokyo, he pledged Washington's "unshakeable" commitment to the security of the region and said Washington wanted to pursue a policy of "pragmatic cooperation" with China, Asia's rising power.
Following the meeting with Mr Medvedev, the US president went on to China.
The BBC's Chris Hogg in Shanghai says the face-to-face talks Mr Obama will have with China's President Hu Jintao will offer an opportunity to take the heat out of some of those trade disputes, and to pursue areas of co-operation, such as technology transfer from the US to help China build a so-called green economy.