NEW DELHI, Oct 21: The United States on Friday made it clear that it was committed to implementing the path-breaking Indo-US nuclear deal even though it was very complex and complicated.

Visiting US Under Secretary of State Nicholas Burns told reporters he expressed the hoped that modalities for resumption of nuclear supplies to Indian reactors would be in place before President George W Bush’s visit here by March.

He, however, said Iran’s controversial nuclear programme might yet prompt the issue to be referred to the UN Security Council if Tehran failed to come to the negotiating table with the European countries by the end of next month. After day-long talks with Indian Foreign Secretary Shyam Saran on a range of issues including Indo-US nuclear deal, he said: “We are not adding any conditions....We Americans will meet the obligations we have undertaken” and hoped India will abide by its obligations.

Both of them said at a joint press conference that the two countries were committed to implementation of the July 18 understanding reached in Washington between Prime Minister Manmohan Singh and President Bush on civilian nuclear cooperation but acknowledged that it was a “very complex” and “complicated” issue.

In reply to question on the Iran issue, Mr Burns bluntly stated that if Tehran did not get back to negotiations with European countries, the Nov 24 meeting of the IAEA would vote against it leading to the issue being referred to the UN Security Council, a move India is trying to avert.

Indian opposition parties and the governments own leftist allies have criticised Dr Singh’s support for the western-led vote at the IAEA board last month against Iran. The government is under severe pressure to abstain from the vote next month.