The United States will contribute to a fund to help poor countries deal with the effects of climate change, a high-ranking Obama administration official said today.
But he said Washington does not see the need to make "reparations" for its centuries of carbon pollution.
"We absolutely recognise our historic role in putting emissions in the atmosphere, up there, but the sense of guilt or culpability or reparations, I just categorically reject that," said Todd Stern, a lead US negotiator to the climate talks.
China said today it wanted the United States to offer sharper carbon cuts by 2020.
Success at the December 7th-18th climate talks in Copenhagen, meant to agree the outline of a new treaty, will hinge on agreement between the United States and China which together emit 40 percent of global carbon dioxide.
Beijing's top climate envoy Xie Zhenhua said the world's biggest emitter wanted to play a constructive role.
Mr Xie urged the United States to increase its planned cuts in carbon emissions by 2020 and said China could "discuss" a target to halve global greenhouse gas emissions by 2050 if developed nations sharpened carbon cuts and raised financial help.
"If the demands of developing countries can be satisfied I think we can discuss an emissions target" to halve global emissions by 2050, he said.
Developed nations want the world to agree a global halving of emissions to indicate that all are willing to take part in the climate change fight. Many developing nations say the rich have to commit to more first.
US officials have vowed support for a deal in Copenhagen. "We are seeking robust engagement with all of our partners around the world," US Environmental Protection Agency Administrator Lisa Jackson said at a press conference.
Reuters