The Indian Prime Minister, who is here on his second visit to Bhutan, inaugurated the Mangdechhu hydroelectric power plant.
He launched stamps to commemorate five decades of India-Bhutan hydropower cooperation.
He also launched the RuPay Card in Bhutan.
Modi and Lotay Tshering (PM of Bhutan) jointly inaugurated the Ground Earth Station and SATCOM network, developed with assistance from ISRO for utilization of South Asia Satellite in Bhutan.
On August 8, 1949 Bhutan and India signed the Treaty of Friendship.
India re-negotiated the 1949 treaty with Bhutan and signed a new treaty of friendship in 2007.
The new treaty replaced the provision requiring Bhutan to take India's guidance on foreign policy with broader sovereignty and not require Bhutan to obtain India's permission over arms imports.
Modi made his first foreign visit as a PM in 2014 to Bhutan.