Iranian President Hassan Rouhani has asked India to invest in infrastructure projects worth $8bn, including an expanded role in developing a strategic port that will open up access to Central Asia, Iran’s envoy to New Delhi has said.

The port of Chabahar in southeast Iran is central to India’s efforts to circumvent Pakistan and open up a route to landlocked Afghanistan where it has developed close security ties and economic interests.

“The potential between Iran and India is great but we were just facing such a wall of sanctions, wall of American pressure,” ambassador Gholamreza Ansari said.

Ansari said that with sanctions likely to be lifted soon, it was a “golden time” for India to seize investment opportunities because of the two countries’ close trade ties and shared interest in improving Central Asian transport links.

India and Iran agreed in 2003 to develop Chabahar on the Gulf of Oman, near Iran’s border with Pakistan, but the venture has moved slowly because of the sanctions over Iran’s atomic programme.

The two countries maintained a close relationship despite the US-led trade restrictions that halved their oil trade to 220,000 barrels per day last year.

In May, India’s Shipping Minister Nitin Gadkari and his Iranian counterpart, Abbas Ahmad Akhoundi, signed an $85 million deal for India to lease two existing berths at the port and use them as multi-purpose cargo terminals.

Under the new proposal India could help build second and third terminals at the port, as well as railway connections into the rest of Iran, Ansari said.