"Brazil has been taking a quite proactive role in the implementation of bio-fuel and afforestaion policies. China and India have also taken steps. But that is not enough, they have to do more," Mr Ban said in an interactive session at the Delhi Sustainable Development Summit.

He said redressal of the climate change crisis was a "common and shared" responsibility and countries of the world should not "argue" on who has to contribute more or less to tackle global warming.

"We should not argue who is more responsible, who is less responsible, who should do more and as to who less. This is a common, shared responsibility," Mr Ban said. India and some of the developing countries have been arguing on the principle of common but differentiated responsibility in tackling global warming citing that they had no share in having caused the problem.

"Just believing that the industrialised countries will be forthcoming in providing technology transfer and financial support... I think all the countries should get onboard, particularly those four (developing) countries should take a leading and positive role," Mr Ban said.

Meanwhile, the United Nations has come out in support of India’s stand of not putting a specific limit on its greenhouse gas emissions asserting that such a cap was not "realistic" and may hamper its economic growth. "I don’t think its possible for developing countries like China and India to cut emissions or say reduce emissions, it is not realistic," Yvo de Boer, executive secretary, United Nations Framework Convention of Climate Change (UNFCCC) told reporters here on Wednesday.

However, he said when the next UN Framework Convention on Climate Change would meet in Copenhagen this December to finalise a new climate change policy, developing countries are expected to bring out proposals to restrict emissions.

"It is feasible and essential that developing countries come forward with ideas to limit their emissions provided international finance is made available for that. Because the bottomline is that if it increases poverty or slows economic growth, it is not a good proposal," he added. As the deadline for Kyoto Protocol ends in 2012, the Copenhagen meet is expected to finalise a treaty to tackle the issues of climate change. There has been a stalemate in negotiations as some industrialised countries want developing nations to define a limit on their greenhouse gas emissions.