He said the flights will allow "my Tamil brothers and sisters" to visit Varanasi, the land of Kashi Viswanath. At a distance of 10 kilometres from Varanasi, lies Sarnath, one of the most revered Buddhist pilgrimage centres.
It is believed that after attaining the enlightenment at Bodh Gaya in Bihar, it was in Sarnath that Lord Buddha preached his first sermon, sanctified as Maha Dharm Chakra Parivartan.
The direct flights will aid pilgrims from Sri Lanka, a Buddhist-majority country, to visit Sarnath.
Varanasi in Uttar Pradesh is PM Modi's parliamentary constituency, from where he contested the 2014 Lok Sabha election.
This is Modi's second visit to Sri Lanka in two years. He arrived yesterday primarily to attend the International Vesak Day celebrations and his visit is aimed at reinforcing the traditional connect between India and Sri Lanka.