Prime Minister Lee Hsien Loong has congratulated his Indian counterpart Narendra Modi on his re-election after a landslide election result.

"The strong mandate reflects the results of your first term and the consequent trust that the people of India repose in your leadership," PM Lee wrote in a letter to Mr Modi, according to a media statement issued yesterday by Singapore's Ministry of Foreign Affairs.

"That the elections were conducted peacefully and smoothly despite the huge logistical challenges is also remarkable," he added.

He said that Singapore appreciates the personal focus that Mr Modi has placed on developing the bilateral relationship, noting that the Indian Prime Minister's steadfast support has helped to catalyse more extensive cooperation across many areas.

He noted that the elevation of relations to a Strategic Partnership in 2015 boosted cooperation in defence, culture and the people-to-people sector.

"Our relations are already very substantial, but we should do more to exploit our complementarities, tap the reservoir of goodwill between the two countries and peoples, and fully realise the potential for enhanced cooperation, including in the fintech and digital space," wrote PM Lee.

He said that Singapore also welcomes India's deepening engagement with the region, in line with Mr Modi's Act East policy and following up on the commemoration of the 25th anniversary of Asean-India relations last year.

"I know you share my conviction that India and Asean can do much more together, to bring mutual benefit and prosperity to our peoples," wrote PM Lee.

"I look forward to working with you to build on the progress we have made. I know you have many domestic priorities, but when your schedule permits, I welcome you to visit Singapore again," PM Lee added, signing off his letter by wishing Mr Modi good health and success in his new term.

Emeritus Senior Minister Goh Chok Tong also wrote a letter to Mr Modi congratulating him on his win.