They say leaders from the Group of Eight industrialized nations are likely to come up with a form of wording which provides a lukewarm acknowledgment of the deal at their meeting in St. Petersburg on July 15-17.

This would boost US efforts to convince the Nuclear Suppliers Group (NSG), the world's top producers of atomic technology, to lift its ban on nuclear trade with India.

"In terms of what the US needs from the G8, this non-committal nod is good enough," said Mark Fitzpatrick of London's International Institute for Strategic Studies (IISS).

"The more important international forum is the NSG, whose 45 members must approve the exception to NSG rules by consensus for the US-India nuclear cooperation deal to be consummated."

India, which has refused to sign the nuclear Non-Proliferation Treaty (NPT), secretly tested a nuclear device in 1974 and then publicly announced a series of tests in 1998, followed shortly afterwards by Pakistan.

The tests led to international sanctions on providing nuclear or dual-use technology to either country.

However last year Washington signed a deal -- yet to be approved by the US Congress -- granting India access to US nuclear fuel and reactors as part of a broader effort to develop US-Indian ties.

Washington had initially hoped the G8 would openly back the deal when the leaders of the United States, Germany, Britain, France, Italy, Japan, Canada and Russia meet.

But concerns about the timing of the deal, which comes as the international community is trying to curtail Iran's nuclear ambitions, and fears it may be rewarding India for flouting the NPT, make a full endorsement impossible, several diplomats said.

"The India language has still not been finalized but will be very neutral," a western G8 diplomat told Reuters on condition of anonymity.

"There will be a lot of 'taking note of India's commitments' and being prepared to look at a new relationship with India that meets its energy needs while being consistent with international non-proliferation norms," he said.

Fitzpatrick, from the IISS, said the lack of opposition from the G8 would be enough to help Washington to try to convince the Nuclear Suppliers Group (NSG) to lift its ban.

The NSG, which was established in response to India's 1974 nuclear test, forbids the sale of sensitive atomic technology to countries not in full compliance with the NPT. India would be the NSG's first exception.

"China's role in the NSG will be key, and it is not part of the G8, of course," he said.

China has traditionally had close ties with Pakistan and might try to block the India-US deal. Japan and many of the 25 EU members also have problems with the idea of rewarding India, diplomats say.

Tacit recognition from the G8 could also help the US administration win approval from the US Congress for the deal, which has run into strong criticism in the United States.