Testing is new wrinkle in Indo-US nuke deal

The testing issue has emerged as the latest wrinkle in the deal, which includes supplying nuclear fuel and reactors to meet India's civilian energy needs.

US Ambassador to India David Mulford expressed confidence the testing issue would be successfully resolved, but acknowledged that Congress may not vote on the deal until after the November election.

The agreement "is being worked on and there will have to be some sort of wording arrangement (on testing), which has not been agreed. It's a matter to be discussed" with India, he told the American Enterprise Institute, a conservative thinktank.

A senior US official close to the negotiations who spoke anonymously told Reuters: "In working out this bilateral agreement, we're going to have to arrive at language -- and I think we can work this out with the Indians."

He insisted the administration is "not rolling back on that commitment ... We're going to maintain our insistence on the moratorium."

The nuclear agreement, underpinning a dramatic improvement in ties between the United States and India has raised concerns that it weakens efforts to curb the spread of nuclear weapons.

India has not signed the nuclear Non-proliferation Treaty and has produced nuclear weapons outside international standards.

In an agreement on civilian nuclear cooperation last July 18, Indian Prime Minister Manmohan Singh made a unilateral declaration that India would maintain a voluntary moratorium on nuclear weapons testing.

The two sides are negotiating a more detailed peaceful nuclear cooperation agreement required by US law, which includes reference to the testing moratorium.