Washington (PTI): Ahead of the crucial IAEA meeting on Friday, a group of arms control experts on Wednesday said both the atomic watchdog and Nuclear Suppliers Group should look at the Indo-US nuclear deal "very carefully and remove all ambiguities."

Sharon Squassoni of the Carnegie Endowment of International Peace cautioned that the "end game" does not stop with the agreement coming before the US Congress for approval but it lies with the 45-member NSG.

"The reality is that the end game is the NSG. India will be able to trade with other states once the 45-member group gives a clean exemption for New Delhi," Squassoni told a press briefing on the subject at the National Press Club.

Ambassador Robert Gray, former US Representative at the Conference on Disarmament, said that the United States was walking away from a treaty signed by 178 nations and termed the agreement as an "unmitigated disaster".

"If any exemption has to come about, it perhaps would have to be addressed by those who initialled the Non Proliferation Treaty," he said.

"The United States has given India a blank cheque... Now we are assisting them (India) to cash the cheque in another Bank, the NSG," he said.

Daryl Kimball, Executive Director of the Arms Control Association and a long time critic of the civil nuclear cooperation between India and US, maintained that the exemption from the NSG is not going to be a "quick one".