FILE - Indian Prime Minister Manmohan Singh greets the crowd during an election campaign rally at Khumtai, in the northeastern Indian state of Assam, Saturday, March 29, 2014. (AP Photo/Anupam Nath, File)

FILE - Indian Prime Minister Manmohan Singh, center, pays floral tributes at Rajghat, the memorial of Mahatma Gandhi, on his death anniversary in New Delhi, India, Monday, Jan. 30, 2014. (AP Photo/Manish Swarup, File)

FILE - Former Indian Prime Minister Manmohan Singh pays homage to former prime minister Rajiv Gandhi on his death anniversary in New Delhi, India, Thursday, May 21, 2015. (AP Photo/Saurabh Das, File)

FILE - Indian Prime Minster Manmohan Singh addresses a press conference, in New Delhi, India, Friday, Jan. 3, 2014. (AP Photo/Harish Tyagi, Pool, File)

FILE - In this Wednesday, May 21, 2014 file photo, outgoing Indian prime minister Manmohan Singh leaves after paying homage to former Indian prime minister Rajiv Gandhi on his death anniversary, in New Delhi, India. (AP Photo/Manish Swarup, File)

FILE - Indian Prime Minister Manmohan Singh speaks during the 68th session of the General Assembly at United Nations headquarters, Saturday, Sept. 28, 2013. (AP Photo/Seth Wenig, File)

FILE - Former Indian prime minister Manmohan Singh, center, gestures after a short meeting with the newly elected office bearers of "National Students' Union Of India" (NSUI), who called on him at his residence in New Delhi, India, Tuesday, March 17, 2015. (AP Photo/Tsering Topgyal, File)