AFP - The White House said Friday the United States was ready to pay a "fair share" of 10 billion dollars a year in climate aid to developing countries as part of a deal at the upcoming Copenhagen summit.

"There appears to be an emerging consensus that a core element of the Copenhagen accord should be to mobilize 10 billion dollars a year by 2012" for developing countries, White House spokesman Robert Gibbs said.

"The United States will pay its fair share of that amount and other countries will make substantial commitments as well."

Senator John Kerry has proposed that the United States pay up to three billion dollars a year for developing countries to cut emissions and cope with climate change to show Washington was serious about a Copenhagen deal.

Britain and France called last week for a 10-billion-dollar fund for developing nations to tackle global warming. British Prime Minister Gordon Brown committed to 1.3 billion dollars.

Gibbs said that Obama discussed the state of play in climate negotiations with Brown, Australian Prime Minister Kevin Rudd, French President Nicolas Sarkozy and German Chancellor Angela Merkel.

"We also need to address the need for financing in the longer term to support adaptation and mitigation in developing countries," Gibbs said in a statement.

"Providing this assistance is not only a humanitarian imperative -- it's an investment in our common security, as no climate change accord can succeed if it does not help all countries reduce their emissions."

Aid is considered a crucial component of a deal as developing nations are resisting demands by Western states and Japan to be treaty-bound to take action on climate change, arguing that rich countries bear historic responsibility.

The United States has shunned the current Kyoto Protocol as it only demands action by rich nations. Its obligations to cut carbon emissions blamed for global warming expire at the end of 2012.

Gibbs also said Obama planned to attend the finale of the climate talks, not next week as previously planned when he will be in nearby Oslo to accept the Nobel Peace Prize.