The United States has said India's willingness to commit a new state-of-the-art facility for reprocessing under International Atomic Energy Agency safeguards was a "fundamental turning point" in the negotiations to finalise the 123
Agreement.

Making it clear that the US would seek return of nuclear technology and fuel if India conducts a nuclear test, Under Secretary of State for Political Affairs Nicholas Burns told reporters in Washington on Friday that Washington would like to see positive cooperation in the realm of civilian nuclear cooperation.

Asked what would happen if the US and India were caught up in a Tarapur-type situation, he said, "It's hard for me to deal in hypotheticals. The fact is that American law insists that the right of return be preserved, and we have preserved that in this 123 Agreement with India."

Burns hoped it won't be necessary for India to test in the future.

"But in the event of any kind of hypothetical disruption of supply, and there is lots of different hypothetical examples that might lead to an interruption of supply, we know it's important for the Indians to have a continuous supply of fuel. And that's why a year and a half ago President George W Bush offered the four fuel assurances that have been written into this law."

However, he stressed that none of that contradicts or conflicts with the legal right of any American president in the future to insist on the right of return.