Accompanied by Sri Lankan President Maithripala Sirisena, PM Modi also unveiled a plaque inaugurating Talaimannar 1650 Pier Railway station.
PM Modi flew to Talaimannar by an Indian Air Force chopper from the ancient holy town of Anuradhapura where he offered prayers at the sacred Mahabodhi tree.
He is on his way to Jaffna, a former war zone in the island's Tamil-majority Northern Province.
The newly-constructed 63-km railway track between Madhu Road and Talaimannar Pier is the last segment of the 265-km long, prestigious Northern Railway Line Reconstruction Project which is being executed by IRCON International Ltd, a Government of India owned company.
It is designed with a speed potential of 120 km per hour. The completion of the rail projects in the northern region is a big step towards providing safe, time and fuel efficient, comfortable and environment friendly transport service to the people of Sri Lanka.
Sri Lankan officials said that after commissioning of the new section, the commitment of the Government of Sri Lanka to restore rail track connectivity in the Northern Province after a lapse of 25 years has been fulfilled.
This will also fulfill the long-cherished dream of the local Tamil people for having direct rail connectivity to Colombo that will also help in the reconciliation efforts of Government of Sri Lanka, they said.