US Ambassador to India David C Mulford on Thursday met Prime Minister Manmohan Singh to discuss the progress on the Indo-US nuclear deal.

Mulford had a meeting with Prime Minister at his 7 Race Course Road residence in the morning hours after Singh returned from his three-day visit to Japan.

Later, Mulford drove down to the South Block and had a meeting with senior officials at the Prime Minister's Office (PMO).

Mulford had on Thursday met the envoys of member states of the 45-nation Nuclear Suppliers Group (NSG) in New Delhi and sought their support for the nuclear accord.

Mulford impressed upon the diplomats that their countries should back the deal as it was in the interest of nuclear non-proliferation system.