The 45-nation Nuclear Suppliers Group (NSG), whose endorsement is crucial to operationalising the Indo-US nuclear deal, will be briefed about the deal by the US in Vienna on Thursday.

The US, which is pushing hard to implement the deal, is expected to explain in detail the importance of change of NSG guidelines to allow international nuclear trade with India.

Against the backdrop political sensitivities back home, Atomic Energy Commission chief Anil Kakodkar is unlikely to attend the meeting. India has to reach a safeguards agreement with the International Atomic Energy Agency (IAEA) soon and secure changes in NSG laws to get the deal going.

Facing questions from Indian reporters here, Kakodkar emphasised that it was US responsibility to get NSG exemption for India. Kakodkar, who is attending the IAEA general conference, underpinned the importance for expeditiously operationalising the deal.

"It is in everybody's interest to conclude the nuclear deal sooner than later."

"Everyone in the nuclear community wants early negotiations between India and IAEA as also the NSG to implement the deal," he said.

But the top nuclear scientist made no direct mention on whether he will discuss the India-specific safeguards agreements with the IAEA during his current visit.

"My lips are sealed on anything to do with the India-specific safeguards," he said.