The U.S. will continue to impose sanctions on whoever purchases Iran's oil or does any business with Iran’s Revolutionary Guards.
Sigal Mandelker, U.S. Treasury Under Secretary for Terrorism and Financial Intelligence, told reporters on Sunday.
Mandelker then noted that Iranian oil sales have taken a "serious nose dive" because of U.S. pressure.
And the chief of the International Atomic Energy Agency said on Sunday that "active cooperation" from Iran was needed on its unravelling nuclear deal with world powers.
The IAEA said on Saturday that it found uranium traces at an Iranian ‘atomic warehouse'.
The agency will hold an emergency meeting on Monday.