Addressing the media at the conclusion of the first of the series of three meetings of major economies of the world, the officials, however, hoped that despite sharp differences, the meeting has increased chances of reaching a new international treaty to tackle global warming.

US Special Envoy on Climate Change Todd Stern said that even as the meeting ended on a very positive note, it does not change the fact that the issues are extremely difficult. "It is not going to be easy to reach agreement," he said in his press briefing after the meeting.

However, the nature of discussion, the substantive quality of interactions, the frankness of the interactions, was all quite encouraging, he observed.

Held at the initiative of the Obama Administration, the meeting included participants from 17 countries - which account for more than 74 per cent of the gas emissions blamed for global warming -- including major industrial powers and key developing economies like India, China and Indonesia.

The two day meeting was the first of the three such preparatory meeting in the run up to the Summit-level meeting of the Major Economies Forum on Energy and Climate scheduled for July in Italy. The next preparatory meeting is scheduled in Paris next month.