Secretary of State Rex Tillerson openly referred to President Donald Trump as a "moron" after a July 20 meeting at the Pentagon, according to NBC News, citing multiple senior administration officials.
According to three officials, Tillerson made the comment in front of members of Trump's national security team and Cabinet members. The report also said Tillerson was on the verge of resigning this summer and had to be talked out of it by Vice President Mike Pence.
Officials said the tensions reached a high point around the time Trump gave a politicized speech to the Boy Scouts of America in late July. Tillerson was once leader of the organization.
The White House was not immediately available for comment when contacted by CNBC and declined to comment on the record to NBC News for the story.
Relations between Trump and the former Exxon CEO appear to still be strained. Just last weekend, Trump publicly denied Tillerson's announcement that the U.S. was attempting diplomatic talks with North Korea.
"I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man...," Trump said in a tweet.
In its report, NBC said Tillerson's top State Department spokesman, R.C. Hammond, denied that the secretary had considered quitting this summer and denied that Tillerson called Trump a "moron."
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