SINGAPORE  President Obama and other world leaders have decided to put off the difficult task of reaching a climate change agreement at a global climate conference scheduled for next month, agreeing instead to make it the mission of the Copenhagen conference to reach a less specific “politically binding” agreement that would punt the most difficult issues into the future.

At a hastily arranged breakfast on the sidelines of the Asia-Pacific Economic Cooperation summit meeting on Sunday morning, the leaders, including Lars Lokke Rasmussen, the prime minister of Denmark and the chairman of the climate conference, agreed that in order to salvage Copenhagen they would have to push a fully binding legal agreement down the road, possibly to a second summit meeting in Mexico City later on.

“There was an assessment by the leaders that it is unrealistic to expect a full internationally, legally binding agreement could be negotiated between now and Copenhagen, which starts in 22 days,” said Michael Froman, the deputy national security adviser for international economic affairs. “I don’t think the negotiations have proceeded in such a way that any of the leaders thought it was likely that we were going to achieve a final agreement in Copenhagen, and yet thought that it was important that Copenhagen be an important step forward, including with operational impact.”

With the clock running out and deep differences unresolved, it has, for several months, appeared increasingly unlikely that the climate change negotiations in Denmark would produce a comprehensive and binding new treaty on global warming, as its organizers had intended.