Secretary of State Rex Tillerson and Defense Secretary Jim Mattis were summoned to the White House to "discuss a path forward" following escalating tensions between Tillerson and President Trump, according to a report Thursday evening.

White House chief of staff John Kelly chaired the meeting Wednesday, opting to stay behind in Washington, D.C., while Trump travelled to Las Vegas to meet with victims and first respondents affected by Sunday's Route 91 Harvest country music festival shooting, per NBC News.

Trump was "furious" at an NBC News report published Wednesday that said Tillerson threatened to resign several times over the summer and called the president a "moron" in a July 20 national security meeting at the Pentagon, six senior administration officials told the news outlet. Trump called that report "fake news" in a tweet.

Seven sources also told the television network that Vice President Mike Pence was enraged by the situation.

Pence and Tillerson reportedly spoke on the phone before Tillerson fronted the media in a press conference in which he apologized to Pence and U.S. Ambassador to the United Nations Nikki Haley, but didn't deny he had disparaged the president.

White House press secretary Sarah Sanders said Thursday that it's "beneath the secretary of state" for Tillerson to weigh in on that report.

The report Wednesday from NBC News quoted Tillerson's top spokesman, R.C. Hammond, saying that Pence had privately questioned the value of Haley in her post at the U.N.

Pence was "very annoyed anyone would misrepresent anything he said, particularly in private meetings," a White House staffer told NBC.

Pence has denied reports on Wednesday that he asked Tillerson to stay on at the helm of the State Department.