India's efforts to get a quick and clean exemption from the Nuclear Suppliers Group for doing nuclear commerce did not materialise on Friday in the face of reservations expressed by some countries that could lead to rewording of the draft waiver.

The 45-nation group will meet early next month, possibly on September 4-5, to consider the changes which US Assistant Secretary of State Richard Boucher said are necessary to accommodate the concerns raised by some countries.

"The meeting was positive... Many delegates raised some questions and the US is pleased (with that). I remain optimistic and we will continue to make progress," John Rood, leader of the US delegation at the NSG meet, told reporters after the two-day discussions.

"The NSG will meet again in the near future to work on these constructive discussions," he said.

After intense deliberations over the move that will end India's 34-year-old isolation in the civil nuclear commerce, diplomats said no final decision could be arrived at.

Further discussions will be required for which the NSG is expected to be convened again on September 4 and 5, they said.

The discussions remained inconclusive as some members raised questions over the move to grant waiver to India since it is not a signatory to the NPT. Indications that the decision could be delayed emerged during the day when Boucher said in Mumbai that some amendments would be made to the draft waiver moved at the NSG.