"This is part of his effort to advance a positive outcome at Copenhagen," the White House said on the eve of Obama's departure for the Denmark Capital.

"President Obama stressed to President Lula the importance of our two countries continuing to work closely to help achieve a robust agreement that makes real progress in forging global action to confront the threat of climate change," the White House said.

Obama noted the key role Brazil is playing, and explained both the steps that have been taken in the United States, and his commitment to an agreement in Copenhagen with emissions reductions, financing, and a transparent and internationally verifiable compliance regime.

He emphasised the need for a strong foundation that includes action by all countries, the statement said.

"With Prime Minister Thomas, whose country chairs the negotiating group for the Alliance of Small Island States, the President stressed the importance of creating a successful framework for emissions reductions and the importance of putting into place suitable financing mechanisms and a transparent and internationally verifiable compliance regime," the White House said.

In the last two days, Obama has had a long conference call with the British, French and German leaders, while he made personal telephone calls to the Prime Ministers of Bangladesh and Ethiopia.