Prime Minister Manmohan Singh's [Images] mood is "upbeat" after the Left parties gave the green signal to the government to approach the International Atomic Energy Agency for safeguard talks in connection with the Indo-US nuclear deal, National Security Adviser M K Narayanan said on Friday night.

"The prime minister called me up (after the Left green signal) and I should think his mood is upbeat," Narayanan told 'Times Now' after the government achieved a major breakthough earlier in the day in breaking the deadlock with the Left over the deal.

Narayanan said the Atomic Energy Commission Chief Anil Kakodkar has been asked to keep his team ready to leave for Vienna to open talks with the officials of the IAEA regarding India-specific safeguards.

Narayanan said the Indian team is expected to leave for Vienna shortly.

The NSA said he was "glad" that the Left clearance had come a few days before the November 20 deadline set for the IAEA talks.

Asked about the timeline for the deal in the next few months, he said February or March 2008 should be an outer limit for the Bush administration to approach the US Congress for the deal's approval as per their legislative calendar.

Therefore, Naryanan said, the IAEA's India-specific safeguards and the amendment to the guidelines of the Nuclear Suppliers Group to faciliate nuclear trade with India should be in place by January.

India has a "rough idea" about the contours of the safeguards, but its final shape can be known only after the Vienna talks.

"The proof of the pudding lies in its eating," Narayanan said.

The talks will be technical in nature and will not be in the form of negotiations, he said.

Asked to comment on the Left go ahead for the IAEA safeguards talks, Narayanan said, "I think it is an opportunte moment. We were looking forward to it. We are glad it came."

Narayanan said the IAEA safeguards talks were crucial for the progress of the nuke deal. "We have to go to IAEA for proper safeguards, India specific safeguards different from the standard set of safeguards."