The tightening of sanctions against Iran is a key plank in the US Government's strategy to cut off the supply of funds for the country's nuclear energy programme.

The proposed measure to cut Iran's central bank and other financial institutions out of the bank-to-bank payments network is part of a package of new sanctions passed by the Senate Banking Committee on Thursday. To take effect, the bill would first need to be approved by the full Senate and enshirned in legislation by the US House of Representatives.

Brussels-based Swift issued a statement saying that it "complies fully with all applicable sanctions laws of the multiple jurisdictions in which we operate and we will continue to do so", citing its ongoinjg role as a key instrument in the global battle against terrorist financing.