Secretary of State Mike Pompeo says the renewed sanctions against Iran are an important pillar in U.S. policy toward the Tehran government.

Pompeo says the sanctions will be rigorously enforced and remain in place until the Iranian government radically changes course.

Those sanctions go back in place on Monday.

Pompeo told reporters on his way home from a three-nation trip to South East Asia that the Trump administration is open to looking beyond sanctions but adds that would "require enormous change" from Tehran.

He said President Donald Trump is intent on getting Iran to "behave like a normal country."

U.S. sanctions had been eased by the Obama administration under the terms of the landmark 2015 Iran nuclear deal. Trump decided in May to withdraw from the accord.