"Discussions are progressing...there are complex issues involved that have to be taken forward step by step," he told reporters on the sidelines of the inauguration of a three day international conference on Nano Science & Technology organised by the Department of Atomic Energy in Chennai.

Asked how soon the talks were expected to be finalised, he said "we would like to do it as fast as possible. But we have to see that India's requirements are properly met".

Kakodkar refused to comment on whether the elections in the US in November, which could signal a change in the White House, would put the deal on the back-burner. "I am a technical person... I do not want to comment on it," he said.

India resumed another round of talks with the IAEA on Monday at Vienna to negotiate the India-specific safeguards agreement which is crucial for the deal.