Trump warns Iran's supreme leader to be 'careful with his words'

"The so-called 'Supreme Leader' of Iran, who has not been so Supreme lately, had some nasty things to say about the United States and Europe," Trump tweeted of Khamenei's comments earlier Friday in Tehran.

According to Trump, Khamenei's blistering speech, in which he attacked the "vicious" United States and described Britain, France and Germany as "America's lackey's," was a mistake.

"Their economy is crashing, and their people are suffering. He should be very careful with his words!" Trump tweeted.