President Barack Obama is shifting the timing of his visit to an international climate summit in Copenhagen as prospects for a political agreement at the event seem more likely.
The U.S., India and China all have specific proposals on the table for the first time, and world leaders are aiming for a deal that includes commitments on reducing emissions and financing for developing countries. They no longer expect to reach a legally binding agreement, as had long been the goal.
Obama is hoping to capitalize on steps by India and China and build a more meaningful political accord, the White House said.
The move means Obama will be at the summit on Dec. 18, considered a crucial period when more leaders will be in attendance, as opposed to his scheduled stop in Denmark on Wednesday on his way to receive the Nobel Peace Prize in Oslo.
It also means that Obama will be squeezing in a separate, 10th foreign trip before Christmas -- a record pace of travel for a first-year president -- as a means to giving momentum to a deal aimed at combatting global warming.
Obama will now leave for Oslo late Wednesday, attend Nobel events Thursday and return to Washington on Friday.
The president had said that he would travel to the Copenhagen conference if his appearance would help clinch a deal. His decision to go early to the two-week meeting had been seen by many as a sign that an agreement was still a long shot.
The possibility of an agreement may be improving, however.
"There are still outstanding issues that must be negotiated for an agreement to be reached, but this decision reflects the president's commitment to doing all that he can to pursue a positive outcome," White House press secretary Robert Gibbs said in a statement. Gibbs said the U.S. will have negotiators involved throughout the Dec. 7-18 conference.
It is also possible that Obama could tack on another agenda item to his revamped, final trip of the year: the signing of a broad treaty with Russia to reduce both nations' nuclear arsenals. The White House had hoped that deal would be ready in time to coordinate it with his receiving the Nobel Peace Prize, but talks have not produced a final breakthrough.
On climate, India pledged Thursday to significantly slow the growth of its carbon emissions over the next decade. China announced its own targets for cutting carbon emissions last week, a day after Obama announced the U.S. goals.
None of the three countries -- which are among the top five emitters of carbon dioxide in the world -- were subject to limits put in place by the 1997 Kyoto Protocol, the treaty that negotiations in Denmark seek to replace.
The development came one day after India said it would cut the ratio of greenhouse gases pollution to production by 20 percent to 25 percent from 2005 levels by 2020 but would not agree to a hard limit on the amount of heat-trapping gases it could release. India's pledge, like the one made earlier by China, is a cut in carbon intensity.
That means emissions can keep rising as their developing economies grow, but they would do so more slowly. China pledged weeks ago to commit to a 40 percent to 45 percent reduction in carbon intensity from 2005 levels over the next decade. That means its emissions would grow at half the rate they would otherwise.
By contrast, the U.S. will propose a cut in emissions over the same time period in the range of 17 percent, regardless of the growth of its economy. For the U.S. to achieve the target it proposes, however, Congress will have to pass legislation to curb greenhouse gases blamed for global warming. The Senate has said it will not take up the measure until next year.
And even if it does, a 17 percent reduction by 2020 is lower than what scientists say is needed to avert the dangerous consequences of climate change.
The Swedish prime minister, Fredrik Reinfeldt, whose country currently holds the rotating EU presidency, said through spokeswoman Roberta Alenius that "it's positive that Obama has decided to participate in the end-phase of the meeting. It will add political weight to the negotiations."
"Hopefully the presence of leaders from the world's largest emitting countries will contribute to bringing the process forward," he said.
Associated Press writer Seth Borenstein contributed to this report.