Boucher also dismissed concerns that the agreement with India may open up an opportunity for Pakistan to seek a similar deal. "India has a long and very solid record of nonproliferation, controlling exports, and a responsible international behavior in that regard," he said.

"So it was considered as an arrangement that worked with regard to India, not as some kind of model for other countries." Boucher especially pushed Japan, which is among the 45 NSG members, to agree to a waiver for India.

"We do understand that Japan's going to have questions and issues that they want to raise, but the bottom line for us is this is the way to get the cooperation we want, this is the way to get the support for non-proliferation, " Boucher said.  

Japanese Foreign Minister Masahiko Koumura had during a visit to New Delhi this week remained non-committal on his country's support saying, Tokyo needed to be convinced that the deal will not undermine non-proliferation efforts.

Komura also pressed India to sign the NPT and the Comprehensive Test Ban Treaty. The board of governors of the International Atomic Energy Agency adopted by consensus on August 1, a safeguards agreement for India, a key step for initiating civilian nuclear cooperation with New Delhi under the deal.

The US will be seeking a waiver from the NSG, comprising countries which export nuclear material and technology, on Aug 21 before the deal is sent to Congress for ratification.

Japan has expressed its understanding on the use of atomic energy for peaceful purposes and had joined consensus to support the India-specific safeguards agreement at the IAEA board of governors.