Secretary of State Rex Tillerson on Wednesday did not deny that he called President Donald Trump a “moron,” amid a bombshell report that his relationship with Trump has been rocky since early in the summer.

NBC News reported early Wednesday morning that Tillerson openly disparaged Trump as a “moron” after a July meeting at the Pentagon, and threatened to resign later the same month after Trump made a political speech at a Boys Scouts rally.

In an unscheduled statement to reporters Wednesday, Tillerson did not deny that he characterized Trump in that way.

“I’m not going to deal with petty stuff like that,” he said.

Trump nevertheless claimed in a tweet after Tillerson’s statement that the secretary of state “totally refuted” the report of friction between them.

The @NBCNews story has just been totally refuted by Sec. Tillerson and @VP Pence. It is #FakeNews. They should issue an apology to AMERICA! — Donald J. Trump (@realDonaldTrump) October 4, 2017

Tillerson claimed NBC News’ report that he had to be talked down from resigning earlier this year was “erroneously reported” and said he has “never considered leaving” his position.

“My commitment to the success of our President and our country is as strong as it was the day I accepted his offer to serve as secretary of state,” Tillerson said. “To address a few specifics that have been erroneously reported this morning, the vice president has never had to persuade me to remain as secretary of state, because I have never considered leaving this post.”

According to NBC News’ report, Vice President Mike Pence, Chief of Staff John Kelly and Defense Secretary James Mattis leapt into action to reassure Tillerson after he threatened to leave Trump’s administration. Pence gave him a “pep talk” and Mattis and Kelly “did beg him to stay,” according to the report. Those efforts ultimately prevailed.

Trump over the weekend did little to contradict reports of conflict, instead undermining Tillerson’s remarks to reporters that the United States has a direct line of communication with North Korea, and is using it for negotiations.

“I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man,” Trump tweeted. “Save your energy Rex, we’ll do what has to be done!”

Nik Steinberg, a former speechwriter and counselor to former United Nations Ambassador Samantha Power, on Wednesday accused Tillerson of “running the State Department into the ground.”

“I know far too many people at the beginning or middle of their careers — with many diplomatic tours ahead of them — who have decided they can no longer bear to serve in the current administration,” Steinberg wrote for Politico. “The U.S. government is quietly losing its next generation of foreign policy leaders.”