"The relationship between India and the United States is singularly important for our society and for the future of American foreign policy," Under Secretary of State for Political Affairs Nicholas Burns told reporters.

"We think, frankly, that one of the most important strategic initiatives of the United States in the last few years has been the opening to India," Burns said.

He made his remarks as Washington dispatched two senior officials to Vienna to sell its controversial nuclear deal with India to the Nuclear Suppliers Group of 44 member states, which seeks to supervise trade in potential nuclear weapons materials. Richard Boucher, US Assistant Secretary of State for South Asia, and Stephen Rademaker, Assistant Secretary of State for International, Security and Nonproliferation, were due to brief members of the group on Thursday about on Washington's plan to provide key US nuclear technology to India, Burns said.

He told reporters in Washington Wednesday that the United States was hopeful about the outcome of the briefings to the group, also known as the NSG.

"My very strong sense is that what we're going to hear tomorrow is a lot of countries are going to wait and see if the United States government is able to convince the US Congress to pass the necessary legislation to allow this deal to go forward," Burns said.

"I think that there'll be a very strong tide of support in the NSG in favour of this, but that's probably a few months away," he said.

The US-India Civilian Nuclear Agreement, sealed on March 3 by US President George W. Bush and Indian Prime Minister Manmohan Singh during a visit by the US leader to New Delhi, would give energy-starved India access to long-denied civilian nuclear technology in return for placing a majority of its nuclear reactors under international inspection.

The agreement, which also places 14 of India's 22 nuclear power reactors under international safeguards, was the cornerstone of Bush's three-day trip to India earlier this month.

"This deal with India is exceptional and it's unique to India, because India is in a unique place. It's a country that wants to come in to a system and live by the worlds rules," Burns said.

He said Washington not only is paying more attention to its bilateral relationship with Delhi, but is focusing more energy and attention on the entire Indian subcontinent.