Newly sworn in as secretary of state, Rex Tillerson shakes hands with Vice President Mike Pence. Getty Images Vice President Mike Pence denied reports that he convinced Secretary of State Rex Tillerson to remain in the administration following an impromptu Wednesday morning press briefing in which Tillerson also denied the reports.

"At no time did he and the Secretary ever discuss the prospect of the Secretary's resignation from the administration," Pence's deputy chief of staff Jarrod Agen said of Pence in a Wednesday statement. "Any reporting to the contrary is categorically false."

Agen also denied the veracity of a claim made by Tillerson's top spokesman, R.C. Hammond, to NBC News that Pence had questioned the value of UN Ambassador Nikki Haley's contributions to the administration.

"The Vice President has known Ambassador Nikki Haley for many years, holds her in the highest regard, and appreciates her strong service to this administration at the United Nations," Agen said.

During an impromptu press briefing on Wednesday, Tillerson denied recent reports that he had ever considered leaving the administration and that Pence had urged him to remain.

"The vice president has never had to persuade me to stay as secretary of state because I have never considered leaving this post," he said. "There's never been a consideration in my mind to leave."

Both before and after Tillerson's press conference, Trump slammed the NBC report on Twitter.

"NBC news is #FakeNews and more dishonest than even CNN," Trump tweeted before Tillerson spoke. "They are a disgrace to good reporting. No wonder their news ratings are way down!"

After the press conference, Trump said in another tweet that Tillerson had denied the NBC report.

"The @NBCNews story has just been totally refuted by Sec. Tillerson and @VP Pence," he tweeted. "It is #FakeNews. They should issue an apology to AMERICA!"

An NBC News spokeswoman told Business Insider on Wednesday that the news organization stands by its reporting. Political reporter Carol Lee said on Wednesday that she and her NBC colleagues "extensively reported" the story, speaking with a dozen sources.

These reports come after months of rumored tensions between the president and his secretary of state.

On Sunday, Trump publicly undermined Tillerson's efforts to negotiate with the North Korean government. Just a day after Tillerson told reporters in Beijing that he had a direct line of communication open with Pyongyang over North Korea's nuclear tests, Trump said diplomacy with the rogue nation was useless.

"I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man," the president tweeted, using his nickname for North Korean leader Kim Jong Un. "Save your energy Rex, we'll do what has to be done!"