India on Friday expressed hope that the final lap of negotiations expected later in May on the agreement to operationalise the civilian nuclear deal with the United States would yield the desired results.

"I am hopeful. We are in for serious negotiations. Talks are going on," Prime Minister Manmohan Singh said on the sidelines of a function in the Rashtrapati Bhavan.

He was asked about reports suggesting road blocks in the proposed talks.

The prime minister is also likely to meet US President George W Bush at the G-8 Summit in Germany commencing early June.

Bush had telephoned Singh earlier this month to give a political push at the highest level to the deal which had got bogged down by hard positions.

The external affairs ministry had on Thursday clarified that no particular date was finalized for the visit of US Under Secretary of State for Political Affairs Nicholas Burns, the key negotiator from the American side, to New Delhi for talks with Foreign Secretary Shivshankar Menon to iron out issues.

During the Menon-Burns meeting in Washington early in May, it was agreed that they will meet again in New Delhi later in May.

India is viewing the upcoming talks on a note of cautious optimism as it is keen to work this out within the benchmarks set out by it.

New Delhi has made it known to its American interlocutors that it cannot close its options for carrying out nuclear tests through any legal binding of its voluntary moratorium.

Unambiguous fuel supply assurances and right to reprocess spent fuel are other important areas on which India is unwilling to make any concessions.

At the same time, New Delhi feels that with the two sides knowing "each other's limits", it was possible to work out the bilateral 123 agreement.

Washington has been objecting to India's insistence on the right to reprocess spent fuel and perennial cooperation even if it were to conduct nuclear tests.