VIENNA: Forty-five nations approved a US proposal on Saturday to lift a global ban on nuclear trade with India in a breakthrough towards sealing a controversial US-Indian atomic energy deal.

One hurdle remained before the US-India deal can take force -- ratification by the US Congress. It must act before adjourning in late September for elections or the deal could be left to an uncertain fate under a new US administration.

The US-India deal raised international misgivings since India has shunned the Non-Proliferation Treaty (NPT) meant to stop the spread and production of nuclear weapons and mandate gradual disarmament, and a companion test ban pact.

Washington says the fuel and technology deal would forge strategic partnership with the world’s largest democracy, help India meet rising energy demand in an environmentally sound way and open a nuclear market worth billions of dollars.

The Nuclear Suppliers Group (NSG) nations adopted a one-off waiver, allowing them to do business with India after several small NSG states agreed under heavy US pressure to weaker language than they had sought to ensure India did not test atom bombs again.

After two weeks of meetings and long-distance consultations, resistance to the exemption finally crumbled when six holdout states accepted revisions to the text, saying it was based on a confidence-building Indian declaration.

Critically, the foreign ministry declaration reinforced a 10-year-old commitment to a voluntary test moratorium. It also said India would not join any future nuclear arms race, would permit broader UN inspections and adhered to the NSG anti-proliferation export control regime.

Ireland, Switzerland, Austria, New Zealand, Norway and the Netherlands had demanded a clause stipulating an automatic cessation of the waiver if India tested another bomb. The waiver hinged as well on “a number of understandings” against exports to India of fuel-enrichment technology able to produce peaceful energy or bombs, diplomats said.

“While we believe this is, in the big picture, an unmitigated non-proliferation disaster, it is still not the clear and unconditional exemption India was demanding,” said Daryl Kimball of the Arms Control Association think tank.

Indian Prime Minister Manmohan Singh greeted the news of the waiver with delight. “The opening of full civil nuclear cooperation between India and the international community will be good for India and for the world,” he said in a statement.

“This is a forward-looking and momentous decision. It marks the end of India’s decades-long isolation from the nuclear mainstream and of the technology denial regime,” he said.

US Secretary of State Condoleezza Rice said: “It is really a very big step forward for the non-proliferation framework.”

Britain’s Foreign Secretary David Miliband said: “We believe it will make a significant contribution to energy and climate security, as well as developmental and economic objectives, for India and the international community.”

But a European diplomat in the Vienna gathering said: “For the first time in my experience of international diplomatic negotiations, a consensus decision was followed by complete silence in the room. No clapping, nothing. It showed a lot of us felt pressured to some extent into a decision by the Americans and few were totally satisfied.”

Diplomats said the final draft cited only the need for a special NSG meeting if India reneged on its commitments.

“The problem here is that the NSG works only on the basis of consensus. So, if India did another test, the follow-up meeting could be reduced to a talk show by any one member like the Americans,” said another diplomat. “It is not clear we could take action as a group,” the diplomat added.