"I think he grew exhausted of me being the guy who told him, 'You can't do that'".
President Trump went after former Secretary of State Rex Tillerson Friday afternoon, calling him mentally deficient for the job and "dumb as a rock". "And if that's what you want to do, there's nothing wrong with that.' I told him, 'I'm ready to go up there and fight the fight, if that's what you want to do'".
Trump announced Tillerson's firing as the nation's top diplomat in a March tweet which named Mike Pompeo as his replacement.
Rex Tillerson has said the president is "undisciplined" and 'doesn't like to read.
"He was dumb as a rock and I couldn't get rid of him fast enough", Trump said on Twitter. He was lazy as hell.
While at the State Department, Tillerson privately fought back against numerous budget cuts the White House enforced on him, but ultimately made deep cuts in staffing that contributed to low morale as veteran diplomats were shown the door or made to feel unwelcome and unvalued.
That led to very public disagreements that undermined Tillerson's ability to speak for the administation overseas and angered the president: "He grew exhausted of me being the guy every day that told him, 'You can't do that, and let's talk about what we can do, '" Tillerson said.
"Now it is a whole new ballgame, great spirit at State!" he said.
Tillerson said on Thursday in Houston that Trump tried to get him to do illegal things without understanding they were illegal.
The former secretary of State also said he believed Trump was able to win the presidency because the public is disengaged on many important issues.
Trump responded to the comments with an angry tweet targeted at Tillerson's intellect. The pair's inability to get along was an open secret, especially after NBC News reported in October 2017 that Tillerson had referred to Trump as a "moron."
Saying Mr Trump won office using modern-day tools to tap into strong emotions, he added, "I will be honest with you".
Tillerson never directly denied the report, saying he wouldn't dignify it with a response.
"If our leaders seek to hide the truth or we as people become accepting of alternative realities that are no longer grounded in facts, then we as American citizens are on a pathway to relinquishing our freedom", he said at the time.