According to Reuters, Russian President and Iranian counterpart, signed a deal to finance and build Iranian railway line as part of an embryonic international North–South Transport Corridor.
As explained, the railway is seen as an important link in the corridor, intended to connect India, Iran, Russia, Azerbaijan and other countries via railways and sea.
As Russia said, this railways can rival the Suez Canal as a major global trade route.
The 162 km (100 mile) railway along the Caspian Sea coast would help to connect Russian ports on the Baltic Sea with Iranian ports in the Indian Ocean and the Gulf.
…said Putin.
Since the 1979 Islamic Revolution that swept U.S.-backed Shah Mohammad Reza Pahlavi from power, Iran has been ostracised by the West and its economy crippled by a myriad of sanctions. It holds around a quarter of the Middle East’s oil reserves.
In conclusion, the West also imposed other set of restrictions over Iran’s nuclear program, while Russia was sanctioned due to its actions in Ukraine.