The two leaders praised each others' efforts to push the deal through
Indian PM Manmohan Singh has met US President George W Bush amid frantic efforts to win US Congressional support for the two countries' nuclear deal.
The controversial accord needs to be pushed through Congress before lawmakers conclude this year's session to campaign for November's elections.
Correspondents say its ratification will be a complicated process.
Reports say the Senate or the House of Representatives is expected to vote on the deal later on Friday in Washington.
"It's taken a lot of work on both our parts, a lot of courage on your part and of course we want the agreement to satisfy you and get it out of our Congress, so we're working hard to get it passed as quickly as possible," President Bush told Mr Singh.
The Indian prime minister replied by saying that he sincerely hoped that this agreement "will be approved in a manner which will be satisfactory from the point of view of both our countries".
"When history is written I think I think it will be recorded that President George W Bush played a historic role in bringing our two democracies closer to each other," he said.
Time running out
Congress is due to go into recess at the end of this week.
The Senate Foreign Relations Committee approved the bill on Tuesday, but there are still several steps to be taken before it can be passed and signed.
The bill has not so far been presented on the floor of the Senate or the House of Representatives.
The deal would give India access to US civilian nuclear technology
Last-minute attempts to ratify the bill have been made more complicated because it was presented late to Congress, which is also debating a critical $700bn bank bailout plan, in addition to numerous other important measures before it shuts down for the year.
Correspondents say that the Bush administration needs the help of the Democrats - who control both houses of Congress - to over-ride a law that says Congress must wait 30 working days after receiving a bill before it can ratify it.
The House and the Senate must pass and send identical bills to President Bush for the deal to go through before a new administration takes office in January.
The Bush administration submitted the deal to Congress on 10 September, but that did not leave enough time for its ratification before the election break without a change in the law.
Correspondents say it will be a race against time if Prime Minister Singh and President Bush sign the deal - first agreed three years ago - and regarded as a key foreign policy priority for both the Indian and US governments.
American lawmakers are now reported to be looking at "all options" to get Congressional approval for the accord, perhaps as part of another bill.
Earlier this month, the Nuclear Suppliers Group lifted a ban that had stopped India from getting access to the global nuclear market.
India says the deal with the US is vital for it to meet its civil energy demands.
But critics 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 agreement is the centrepiece of US efforts to bolster ties with India.
The US restricted nuclear co-operation with India after it tested a nuclear weapon in 1974.