"It may be one of those cases where we notify the Congress and then it has like 30 business days to offer an opinion. If it doesn't offer an opinion, then it goes into force," State Department spokesman P. J. Crowley told reporters on Thursday.

"We'll get you an answer in terms of the procedure. We'll get that answer," he said when asked if the Barack Obama administration had sent the agreement announced March 29 for Congressional approval.

The agreement that would allow spent nuclear fuel from two reactors to be set up by US companies at two dedicated facilities in India was one of the few remaining steps in the way of implementing the landmark India-US civil nuclear deal.

The US side is now awaiting the passage of a nuclear liability law by India to enable American companies to take advantage of  an estimated $150 billion nuclear power market opening up in India.