US President Donald Trump repeated his threat on Sunday to resume strikes against Iran, saying during an election rally that he might have to deliver a "crushing blow" to Tehran at an unspecified time.

Trump stated to his supporters during an election rally in the state of Iowa ahead of the midterm elections scheduled for Tuesday, "And the only reason I haven't finished with Iran yet... is because I want to be nice. I want to try to save all those lives if I can... but at some point, we will have to deliver a crushing blow to them."