Tharoor, former Union Minister and Lok Sabha member from Thiruvananthapuram constituency, termed the US President's profile of Modi as a "remarkable gesture".
"A remarkable gesture by a US President. Whatever our political differences, Indians hope @narendramodi lives up to it," Tharoor said in a Facebook post and on Twitter.
Tharoor had drawn flak from Kerala Pradesh Congress Committee for responding positively to Modi's invitation to him for the "Swachh Bharat" campaign.