With the clock ticking, President Obama will travel to Copenhagen tonight in a last-minute attempt to finalize a global climate change agreement that has become mired in debate in recent days.
After an overnight flight from Washington, Obama will join more than 100 world leaders who are gathered on the last day of the United Nations conference to try and reach a deal .
German Chancellor Angela Merkel and Australian Prime Minister Kevin Rudd have expressed frustration at the lack of progress in Copenhagen, with Rudd admitting that the negotiations were "sticky."
Obama's arrival at the table is seen as a strong signal that a final deal is possible, but negotiators are continuing to hash out details on the eve of his arrival.
The Obama administration dispatched its top diplomat -- Secretary of State Hillary Clinton -- to Copenhagen Wednesday as the prospects of an agreement seemed to diminish in an ongoing dispute between the United States and China on the transparency of emissions reductions.
Clinton landed in the Danish capital today and announced that the United States would contribute an unspecified amount to a $100 billion fund to be established by 2020 to help poorer countries switch to more energy efficient technologies. The news was widely viewed as a shot in the arm for the ongoing discussions.
"We're running out of time," Clinton told reporters at a news conference shortly after arriving. "Without the accord, the opportunity to mobilize significant resources to assist developing countries with mitigation and adaptation will be lost."
Among the roadblocks for a deal is a disagreement with China, one of the world's largest emitters of carbon dioxide, about verification of emissions cuts. A U.S. official is reported as saying China was not willing to sign onto an accord immediately, although Chinese officials have reportedly denied that account.
Clinton met with Chinese Premier Wen Jiao Bao today, but it was unclear whether the discussions were able to break the logjam.
The White House said today that Obama hopes his attendance at the summit with push talks forward. But spokesman Robert Gibbs said the president has never been under any illusion that a deal would be easy.
"We're not going there just to get an agreement for the sake of something that's called an agreement," Gibbs said. "We want something that works for both the international community but also what works for the United States. We think the elements are there to reach that agreement."
The president is facing pressure to return from the conference with tangible results, and his critics have noted that the last time he went to Copenhagen -- to make a last-minute pitch for Chicago's failed Olympic bid -- he came up short.
Gibbs said today that coming back with an empty agreement would be far worse than coming back empty-handed. But if no final climate agreement is reached, Gibbs said, Obama is committed to continuing to work on the issue.
For her part, Clinton tried to play down the notion of a U.S.-China showdown as the clock ticks down on a potential deal.
"We have lost precious time in these past days," Clinton said. "In the time we have left here, it can no longer be about us versus them -- this group of nations pitted against that group. We all face the same challenge together."