Also, U.S. making progress with China at U.N. Climate talks. Uh-Oh.
Obama leaves Washington later on Thursday and is expected to arrive in Denmark around 8 a.m. local time on Friday, U.S. officials told reporters on a conference call.
He will give a brief address at a plenary session with other world leaders and emphasize the renewed U.S. commitment to show leadership on global warming, but he is not expected to be more specific about Washington's pledge to help provide funding for poor countries dealing with climate change.
That pledge is tied to monitoring, reporting and verification requirements by China and other big developing countries on their emissions curbs. China has resisted such requirements.
One U.S. official said progress was being made on that issue and others ahead of Obama's arrival.
"We're making progress on all of our outstanding issues with the Chinese. We have a good dialogue going and there are other parties as well," the official said.
"There's still a way to go on all the issues and there's not much time left, so we certainly can't predict at this point what the outcome of the conference will be," he said.
Obama, who delayed a decision on whether to attend the talks until just weeks ago, is staking his credibility on the still elusive deal with ramifications for him at home and on the world stage.
Asked whether the president was concerned about returning empty-handed from Copenhagen for a second time this year after failing to secure the 2016 Olympics for Chicago, White House spokesman Robert Gibbs said, "Coming back with an empty agreement would be far worse than coming back empty-handed."
With his top domestic legislative priority of healthcare reform percolating in Washington, the president plans to stay in Copenhagen less than a day.
That may or may not be enough time to overcome persistent disagreements between developed and developing nations that have marred two weeks of talks, but Obama's presence and contribution could be a potential deal-maker.
The United States tried to break a deadlock on Thursday, with Secretary of State Hillary Clinton announcing that Washington was prepared to help mobilize $100 billion a year by 2020 to assist poor nations dealing with climate change.
Gibbs said the United States still believed an agreement at Copenhagen was possible.
"We want something that works for both the international community but also that works for the United States. We think the elements are there to reach that agreement," he said.
The United States has proposed cutting its greenhouse gas emissions in the range of 17 percent by 2020 compared with 2005 levels. That corresponds to a 3 percent reduction from 1990 levels, the baseline used by the European Union and others.
Obama is unlikely to propose a more aggressive emissions reduction target, which many countries have demanded. His goals are based on a bill that passed the House of Representatives but has yet to go through the Senate.
Environmentalists say Obama could turn the talks around by pledging his strong support for the Senate climate bill, which has a more aggressive 20 percent emissions reduction target, and by putting his full efforts into the issue once healthcare reform is finished.
An official on the conference call said the administration would make a "robust" effort to advance the bill next year.
Obama's participation is fraught with risks. If the president, a Democrat, puts a more aggressive offer on the table in Copenhagen, he could face criticism from Republicans who charge the United States is going too far without getting enough in return from big developing economies such as India and China.
If he is more cautious and the talks end up faltering, he would be connected to that failure and his efforts to pass domestic climate change legislation could suffer along with his credibility among other international leaders.
"He's sort of damned if he does, damned if he doesn't, and (so) he might as well do the thing that's right," said Alden Meyer, director of strategy and policy at the Union of Concerned Scientists, urging Obama to push the talks forward.