U.S. President Barack Obama said the UN climate change Copenhagen conference is a "meaningful and unprecedented breakthrough."
"For the first time in history all major economies have come together to accept their responsibility to take action to confront the threat of climate change," he said.
Since December 7, delegations from 193 countries have been negotiating global measures to curb greenhouse gas emissions at the UN Climate Change Conference in Copenhagen.
Obama said he negotiated throughout the day with the leaders of China, India, Brazil and South Africa and they came to an agreement, which would be "an important milestone."
"We agreed to set a mitigation target to limit warming to no more than 2 degrees Celsius, and importantly, to take action to meet this objective consistent with science," the U.S. president said.
The 15th UN climate change conference is the result of two years of international talks on a binding treaty to cut global carbon emissions. The talks brought together about 15,000 participants from 192 countries.
Scientists have warned that the emissions cuts so far offered at the summit would fail to prevent a catastrophic rise in temperatures.
The Kyoto Protocol, a legally binding agreement restricting carbon emissions, expires in 2012. A new deal is needed to continue efforts beyond 2012.
The United States did not sign the original Kyoto Protocol.
MOSCOW, December 19 (RIA Novosti)
