OSLO: The United States promised yesterday to take "ambitious actions" under a new UN pact to fight global warming and urged a dramatic increase in cash to help developing nations cope with climate change.

A submission to the United Nations outlining Washington's ideas for a treaty due to be agreed in Copenhagen in December also said many nations should outline greenhouse gas cuts both for a mid-term goal of 2020 and a long-term 2050 target.

"The United States is committed to reaching a strong international agreement in Copenhagen based on both the robust targets and ambitious actions that will be embodied in US domestic law," it said.