Many Asia-Pacific leaders agreed on Sunday that it was unlikely they would clinch a legally binding deal at next month's climate change talks in Copenhagen, a U.S. official said.
"I don't think the negotiations have proceeded in such a way that many of the leaders thought it was likely that we were going to achieve a final agreement in Copenhagen," a top U.S. negotiator, Michael Froman, told reporters.
"And yet they thought it was important that Copenhagen be an important step forward, including with operational impact."
Froman was speaking after a breakfast meeting of 19 of the 21 leaders at an Asia Pacific Economic Cooperation (APEC) meeting in Singapore, the last major gathering of global decision-makers before Copenhagen.
Present at the meeting were Obama and the leaders of China, Japan, Russia, Australia and Indonesia.
The leaders heard a speech by Danish Prime Minister Lars Lokke Rasmussen, host of the Copenhagen talks, who is hoping for a political deal to replace the Kyoto Protocol, leaving legally binding decisions until later.
With Kyoto's first phase set to run out in 2012, the December 7-18 Copenhagen talks are seen as the last chance for all countries to agree on painful measures needed to ease the pace of climate change.
The aim of the U.N. meeting is to set ambitious targets for cutting greenhouse gases, but also to raise funds to help poor countries tackle global warming.