The US Treasury also announced new sanctions targeting Iran's financial, cryptocurrency, rail, automotive and manufacturing sectors. (EPA Images pic)

WASHINGTON: The US on Monday warned foreign financial institutions that if they conducted any business with Iran or its banking sector they could be sanctioned by Washington.

"Foreign financial institutions continuing to transact with sanctioned Iranian financial institutions could be targeted at any time without advance notification and should take immediate action to terminate such activity and relationships," the US Treasury said in an "alert" statement.

The United States launched its war against Iran in late February, killing the country's leadership and demanding it cease any nuclear-related activities.