Trump rages at 'lazy' Rex Tillerson: He lacked the 'mental capacity' to be secretary of state

Donald Trump on Friday attacked Rex Tillerson, after his former secretary of state said the president was undisciplined and wanted to violate the law.

"Mike Pompeo is doing a great job, I am very proud of him. His predecessor, Rex Tillerson, didn’t have the mental capacity needed. He was dumb as a rock and I couldn’t get rid of him fast enough. He was lazy as hell. Now it is a whole new ballgame, great spirit at State!" Trump tweeted.

Tillerson, who was fired in March via a tweet, said Thursday night that Trump had to be repeatedly warned that his proposals were illegal.

“So often, the president would say, ‘Here’s what I want to do and here’s how I want to do it,'” he explained. “And I would have to say to him, ‘Mr. President I understand what you want to do but you can’t do it that way. It violates the law.'”

"It was challenging for me coming from the disciplined, highly process-oriented ExxonMobil Corp to go to work for a man who is pretty undisciplined, doesn't like to read, doesn't read briefing reports, doesn't like to get into the details of a lot of things," Tillerson added.

During his time as Trump's secretary of state, Tillerson was accused of describing the president as a "moron" in a Pentagon meeting.