Washington (CNN) As warning signs of an economic slowdown bubble up at home, President Donald Trump has amped up his trade war with China. And he's using a ... unique ... way to do so.

"Our great American companies are hereby ordered to immediately start looking for an alternative to China," Trump tweeted on Friday. While the statement immediately ricocheted through the media, Trump's authority to "hereby order" companies to do something does not exist

Trump didn't reserve his ire for China this week, either. "My only question is, who is our bigger enemy, Jay Powell or Chairman Xi?" Trump mused on Twitter on Friday.

Trump appointed Powell the chair of the Federal Reserve in 2018, but has (apparently) soured on the pick. "Our Federal Reserve does not allow us to do what we must do. They put us at a disadvantage against our competition," Trump tweeted on Thursday. He also said Wednesday that Powell had raised interest rates "too fast, too furious."