Iran sanctions: US warns foreign financial firms

The United States warned foreign financial institutions Monday that they could face Washington sanctions if they do business with Iran or its banking sector.

The US Treasury said in an alert that foreign financial institutions continuing to transact with sanctioned Iranian financial institutions “could be targeted at any time without advance notification” and should end such activity and relationships.

The Treasury said Iran's government operates “shadow banking” channels to get around US sanctions, and said foreign financial institutions should work to identify and avoid such activity.

Washington has stepped up efforts since late August to economically isolate Tehran, warning allies that they could face secondary sanctions if they continue transactions with Iran's government. The Treasury has also announced sanctions targeting Iranian financial, rail, automotive and manufacturing sectors, and has taken action against banks in the United Arab Emirates and Turkey over alleged aid to authorities in Tehran.

The warning comes during the war launched by the United States against Iran in late February, which has driven violence across the Middle East and disrupted a key trading route, sending global energy and fertilizer prices higher.