President Donald Trump on Friday warned Iran's supreme leader, Ayatollah Ali Khamenei, to be "very careful with his words." Trump tweeted after Khamenei's comments earlier on Friday, "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". 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 added.