India made official a $500m investment for the development and operation of an Iranian port, with an eye to energy export markets.

During a state visit this weekend, Indian prime minister Narendra Modi signed a deal with Iranian president Hassan Rouhani for the Chabahar port, near the Pakistani border in the Arabian Sea.

The port would be an entry point for finished goods imports from India to more easily reach landlocked markets such as Afghanistan and central Asia via rail or truck.