Tesla and SpaceX CEO Elon Musk tore into Peter Navarro, senior counselor for trade and manufacturing for President Donald Trump, in a post on X late Friday.

"A PhD in Econ from Harvard is a bad thing, not a good thing. Results in the ego/brains>>1 problem," Elon Musk wrote in response to a video of Navarro discussing Trump's tariffs on a host of countries on CNN.

In response to an X user posting in defense of Navarro, Musk wrote: "He ain't built s--t."

Trump's announced a baseline 10% tariffs on imports this week. He also said he would implementing higher tariffs on goods imported from a large group of countries.