The House Appropriations Committee has approved a law banning the US Export-Import Bank from helping firms that supply gasoline to Iran or support its production at home.

The intention is to put pressure on Iran for relinquishing its nuclear program, which the US and the West allege has military purposes. Tehran has repeatedly declined the claim, saying that nuclear weapons do not fit in its defense paradigm.

Earlier contracts were awarded by US Energy Department to provide crude to the US reserve to three of Iran’s gasoline suppliers: Vitol Group, Royal Dutch Shell plc and Glencore International AG.

A emergency petroleum reserve was created by US Congress in the mid 1970s and around 724 million barrels of crude is stockpiled at four underground storage locations in Texas and Louisiana.