Iranian President Hassan Rouhani on Sunday inaugurated the first phase of Chabahar port, also known as the Shahid Beheshti port.
The port opened Afghanistan and Central Asia to Indian commerce while isolating Pakistan.
Giving a boost to the bilateral ties between India and Iran, External Affairs Minister Sushma Swaraj has made an unannounced visit to Tehran, while returning from Sochi in Russia, ahead of the inauguration of the strategically important port.
Over a month ago, India sent the first consignment of wheat to Afghanistan through Chabahar Port, which Swaraj remarked as a gift from Indians to Afghans.
Swaraj then said that India remains committed to work closely with its regional and international partners to bring peace, security, stability and prosperity in Afghanistan.
India has committed $500 million to build the port to bypass Pakistan.
The port located on the coast of the Gulf of Oman in Iran's southeastern Sistan-Baluchestan province has two docks.
Iran has invested about one billion dollars in building the first phase of the port.
Director General of Ports and Maritime Organisation in Iran's Sistan and Baluchestan Province, Behrouz Aqaee, said
about 100,000-tonne ships will be able to call at the port after it becomes operational.
The inauguration of the port was attended by delegates from 27 countries.