Foreign Secretary Shyam Saran and US Undersecretary of State Nicholas Burns held restricted meeting followed by a delegation-level meeting, official sources said.

Apart from discussions on the road-map for implementation of the nuclear cooperation agreement, the meeting was also expected to take up Iran's nuclear issue.

Ahead of the two-day meeting, Burns said the two countries had "ventured into a unique international diplomacy in our bilateral atomic relations."

He said in Mumbai on Wednesday that India and the US have committed to try and achieve civil nuclear agreement between the two countries."

According to him, it would take around six to eight months to "decide on how best to proceed" and put that into a bilateral programme that President George W Bush and Prime Minister Manmohan Singh could agree upon finally as the way ahead.

At the last meeting between Saran and Burns in Washington in December, the Indian side had unveiled its plan of separating civilian and military nuclear establishments as required under the deal. The plan would be put up before the US Congress for endorsement.

New Delhi expects a response from Washington to its plan at the meeting.

The Prime Minister has maintained that the deal was based on "strict reciprocity" as per which India will present its plan for separation and simultaneously the Bush administration should approach the Congress for endorsement.

The US government has been insisting that it would approach the Congress when it felt India's plan was "credible".

Burns said on Wednesday that apart from the nuclear issue, the US was also keen towards agricultural research, energy needs, infrastructure development space and higher education.

"We want to explore whether both the governments could do more in agricultural research with combined involvement of our universities and Indian technical institutes," he said.

Significantly, prior to the meeting, several US MPs have voiced support for the deal.