Trump says protest-hit Iran in 'big trouble,' again threatens strike

US President Donald Trump said Friday that Iran, faced with major protests, was in "big trouble" and again warned he could order military strikes.

"Iran's in big trouble. It looks to me that the people are taking over certain cities that nobody thought were really possible just a few weeks ago," Trump said, reports AFP.

Asked on his message to Iran's leaders, Trump said, "You better not start shooting because we'll start shooting too."

"If they start killing people like they have in the past, we will get involved," Trump said.

"That doesn't mean boots on the ground, but it means hitting them very, very hard where it hurts."