In a veiled answer to Left and other critics of the Indo-US nuclear deal, External Affairs Minister Pranab Mukherjee on Friday asserted that the country needed nuclear power to meet its energy needs while addressing environmental concerns.

As he held talks with his Thai counterpart Nitya Pibulsonggram in Bangkok on a wide range of issues, including possibility of civilian nuclear cooperation, Mukherjee said the international community could have trade with India after a safeguards agreement is in place.

Addressing a joint press conference with Pibulsonggram after the talks, Mukherjee said India needed to diversify the sources of energy as it could not depend only on fossil fuels and hydro-power.

"It is clear that India is an energy deficient country and requires energy from various sources," he said.

He noted that nuclear energy is one of the cleanest sources of energy, 'which we can have,' keeping in view the worldwide concerns of climate change, carbon emissions and high technology cost of moving to other sources.

"We do feel that nuclear energy is appropriate as an alternate source of energy," he said.

The comments can be seen as a reply to Left parties, which are criticising the Indo-US nuclear deal.

Allaying fears of skeptics, Mukherjee said India has an "impeccable record" on the non-proliferation front and that he had conveyed the same to his Thai counterpart.

He said India's nuclear programme was the result of its own scientific research and development and not an outcome of any "clandestine" dealings.

"We have maintained strict control on export of nuclear technology... The strategic programme and peaceful programme of nuclear energy are separated in watertight compartments," the external affairs minister underlined.

He said whatever fuel comes from Nuclear Suppliers Group members and other countries will be subjected to "safeguards prescribed by the IAEA through the India-specific safeguards agreement. There is no question of its diversion."

He pointed out that at present, India does not have access to fuel and technology.

"We are debarred from nuclear trade," he said, adding that "However, once India-specific safeguards agreement is in place, it will be available."

India will have to 'overcome' three stages -- safeguards agreement with the UN atomic watchdog, IAEA, exemption from NSG and getting approval of US Congress -- before the international community can start trade with it, he said.