The 17 major economies in the forum are Australia, Brazil, Canada, China, the European Union, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, South Africa, South Korea, the United Kingdom and the United States.
President Obama has made the fight against climate change a key priority of his Administration since he took office in January.
The announcement of the Major Economies Forum came as the latest round of UN climate change talks kicked off in Bonn, with 190 nations meeting to work on an international pact to be agreed in Copenhagen.
US Climate Envoy Todd Stern told delegates at the Bonn meeting that the US is 'very glad to be back' in the negotiations – in a reference to the Bush Administration, which never ratified the Kyoto Treaty.
'We want to make up for lost time, and we are seized with the urgency of the task before us,' Stern said to loud applause from the 2,600 delegates.