The head of the United Nations's scientific panel on climate change said in an interview published Monday that developing countries were unwilling to sign up to a global deal on cutting carbon emissions because rich countries were not leading the way.

"Looking at the politics of the situation, I doubt whether any of the developing countries will make any commitments before they have seen the developed countries take a specific stand," Rajendra Pachauri of the Nobel Prize-winning Intergovernmental Panel on Climate Change told The Guardian.

Pachauri said that while Germany was setting a positive example and Britain was doing "quite well", there were still "reasons for dismay" at many rich countries' failure to cut their carbon emissions.

"In several developing countries you get the feeling -- in fact people state it very clearly -- that these guys (rich countries) are going to shove the whole burden on to our shoulders. That's why it's necessary for the developed world to establish a certain credibility."

He added that China and India, fast-growing countries regarded as essential signatories for any climate deal to have an impact, "would like to see some level of ambition on the part of the developed countries before they make any voluntary commitments of their own."

Pachauri noted, though, that there was still time to get the two countries on board with an agreement, but several "measures and actions" would be necessary over the coming months, such as ambitious carbon-reduction targets for the next decade from rich countries and more money to help poorer countries adapt to global warming.