"The President believes that we can get an operational agreement that makes sense in Copenhagen over the next few days," White House spokesman Robert Gibbs told reporters at his daily briefing.

On the conference call with British Prime Minister Gordon Brown, German Chancellor Angela Merkel and French President Nicholas Sarkozy, Obama talked about the climate change negotiations that are currently going on in Copenhagen.

"This conference was one of a number of conversations that the President has held with leaders from around the world in the last few days. A day earlier Obama called Prime Ministers of Ethiopia and Bangladesh," Gibbs said.

"I believe that all of these countries share the strong goal of getting something done by the end of this week in Copenhagen. The President certainly shares that and believes that we can make progress assuming we meet some of those operational goals," he said.

Obama reviewed efforts by the US on climate change, reiterated his commitment to making progress towards a successful conclusion of an operational agreement in Copenhagen, he said.

"Other leaders described efforts that Europe was making, all committed to working together. They will be all getting together in the coming days, and the President believes that we can get an operational agreement that makes sense in Copenhagen over the next few days," Gibbs said.

"I think the President has been clear in setting forth a robust goal for the United States to meet by 2020. We have voiced our support for financing through 2012. We have worked with China and India to bring them along in this process to the point where they have now released specific goals for decreasing their carbon intensity between now and 2020," he said in response to a question.

Acknowledging that there are issues that exist, Gibbs said Obama believes that to get an agreement that is truly operational, there needs to be transparency. "That's one of the things that he'll work on as we go forward," he said.