After talks, which went on late into the night on Friday, Dec 18, US and BASIC countries Brazil, South Africa, India and China reached a legally non-binding with transparency in emission cuts, mitigation targets and finance forming the basis of the common approach.
Speaking to reporters after several hours of discussions with Indian Prime Minister Manmohan Singh and leaders of China, Brazil and South Africa, Obama said, "Today we've made meaningful and unprecedented - made a meaningful and unprecedented breakthrough here."
"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.
A US official who termed this a 'important first step', however, pointed out that this was not sufficient to fight climate change and global warming.
"No country is entirely satisfied with agreement, but it is historic step forward to be built on later," the official informed, adding that countries "agreed to give information on their emissions through national communications, with possibility of international consultations.