Saran -- the prime minister's special envoy on climate change and the India-US nuclear civilian agreement -- also confirmed that Prime Minister Manmohan Singh [Images] will attend the G-8 summit in Tokyo later this week.

He, however, clarified that the government has not yet given the go-ahead for negotiators to approach the International Atomic Energy Agency in Vienna and finalise the safeguards agreement there.

"We have more or less finalised the IAEA safeguards agreement," Saran told CNN-IBN's Suhasini Haider in an exclusive interview, "And the remainder won't take much time. But we await the government's go-ahead to approach the IAEA."

Dr Singh will meet US President George W Bush [Images] and other international leaders as part of the O-5 (the Outreach five nations), where the nuclear deal and climate change initiatives are expected to form an important part of the negotiations.

Saran said the imperative to move from 'fossil-fuels to non-fossil and renewable energy sources' is one of the reasons nuclear energy is an important part of Indian initiatives to tackle global warming.

His comments are significant against the backdrop of Left party leaders saying the timing of their withdrawal of support to the government now hinges on the prime minister's decision to go to the G-8 summit.