TIMETABLE FOR NUCLEAR ACCORD
Approval required from 45-member Nuclear Suppliers Group
US Congress to approve deal before President Bush signs it into law
All this to happen before Mr Bush's tenure expires in January 2009
A group of nations that regulate global nuclear trade is meeting for a second day to consider lifting restrictions on selling nuclear technology to India.
It is part of a controversial Indian-US deal that needs the approval of the 45-nation Nuclear Suppliers Group (NSG) before the US Congress can ratify it.
The group did not endorse the plan in a meeting last month, forcing the US to come back with a revised proposal.
India's government says the deal is vital to meet its civil energy demands.
Critics of the deal say it creates a dangerous precedent - effectively allowing India to expand its nuclear power industry without requiring it to sign the Non-Proliferation Treaty (NPT) as other nations must.
They say the deal would undermine the arguments for isolating Iran over its nuclear programme and be a disaster for international non-proliferation efforts.
The US restricted nuclear co-operation with India after it tested a nuclear weapon in 1974.
The current deal is the centrepiece of US efforts to bolster ties with India, but the agreement looks to be in deep trouble, says the BBC's diplomatic correspondent Jonathan Marcus.
Reports say that some members of the NSG meeting in Vienna expressed concern that the latest US revisions were cosmetic and did clarify whether the deal would enable India to subvert agreements meant to stop production and testing of nuclear weapons.
India's communists oppose a partnership with the US
An unnamed diplomat was quoted by the Reuters news agency as saying that the "outlook for consensus is dim because India and the US won't accept any references in the waiver text to automatic cessation of trade in case India tests another nuclear weapon".
But a report in the Washington Post newspaper said that the Bush administration had told the US Congress in a "secret" letter that the US had the right to stop nuclear trade with India should the latter conduct a nuclear weapons test.
The letter to the late Tom Lantos, chairman of the House of Representatives Foreign Affairs Committee, said: "The fuel supply assurances are not, however, meant to insulate India against the consequences of a nuclear explosive test or a violation of non-proliferation commitments."
India's main opposition Bharatiya Janata Party (BJP) and the communists - former allies of the governing Congress party who withdrew support for the government over the nuclear deal - have said the contents of the letter show the government is "deceiving" the country.
"There is a huge difference between what the US government is telling its Congress and what our government is telling us," BJP leader Yashwant Sinha told reporters.
However, even if opponents give way, there will be insufficient time this year for the US Congress to endorse the deal.
Under the terms of the deal, India would open 14 civilian nuclear facilities to inspection - but its nuclear weapons sites would remain off-limits.
Critics fear assistance to India's civil programme could free-up additional radioactive material for bomb-making purposes.