(CNN) Secretary of State Rex Tillerson said he has no plans to resign and will not do so, denying reports that Vice President Mike Pence had to urge him to stay in the job and sidestepping questions about whether he called President Donald Trump a "moron."

"The vice president has never had to persuade me to remain as secretary of state because I have never considered leaving this post," Tillerson said in a hastily called press conference at the State Department.

Tillerson's remarks were part of an administration wide effort to dismiss an NBC article in which aides described Tillerson calling Trump a moron and his "fury" about the ways Trump has undermined him publicly on several foreign policy initiatives. Calling the report "erroneous," Tillerson pointed the finger at "some who try to sow dissension" to undermine the President's agenda. And he said he wouldn't deal with "petty nonsense" of name-calling.

Asked whether he'd ever called Trump a "moron," Tillerson did not respond directly.

"The places I come from, we don't deal with that kind of petty nonsense," Tillerson said. "I'm just not going to be part of this effort to divide this administration." He spoke as the President was flying cross country to visit survivors of Sunday's mass shooting in Las Vegas.

It was a remarkable public defense that only served to highlight administration infighting and the President's precarious track record with his most senior officials and advisers, some of whom have resigned or been dismissed, and others, such as Attorney General Jeff Sessions, who have had to endure public excoriation from Trump.

Trump was aware before Wednesday's report that Tillerson had referred to him as a "moron" at the Pentagon this summer, a source familiar with the conversation told CNN, but it's unclear whether Trump discussed the remark with Tillerson. Trump was not present at the Pentagon meeting. A White House source also confirmed to CNN that Trump knew about the insult prior to Wednesday.

Trump is not pleased that it is now public knowledge that Tillerson called him a "moron," but he isn't on the verge of asking for his top diplomat's resignation, a person familiar with his thinking said. On Thursday morning, the President tweeted that Tillerson never threatened to resign.

Instead, the President publicly dismissed the report as "fake news" and "totally made up" while on a trip to Las Vegas. The President said he had "total confidence" in Tillerson.

"An uneasy relationship"

Privately, however, Trump and Tillerson have an uneasy relationship, the source said, but Trump is wary of another high-profile departure from his administration after a tumultuous eight months in office. He's aware that his administration and inner West Wing operation are shedding staff at an alarming clip, the person familiar with his thinking said.

Trump has either dismissed or seen the departure of a national security adviser, press secretary, communications director, chief strategist, acting attorney general, FBI director and -- as of Friday -- a health and human services secretary.

Trump, above all, wants to project a sense of competence and believes the rapid turnover of staff helps fuel the notion his administration is in chaos, according to the source.

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The President's rocky track record on senior staff and the ongoing rumors that Tillerson may leave or be ousted has raised concerns that the top diplomat's departure could disrupt national security interests at a time when Washington faces multiple international challenges.

"I think Secretary Tillerson, Secretary Mattis and Chief of Staff Kelly are those people that help separate our country from chaos," Sen. Bob Corker, the Tennessee Republican who chairs the Foreign Relations Committee, told reporters Wednesday.

State Department spokeswoman Heather Nauert said Tillerson spoke with Trump after his remarks to the press and told her that "it was a good conversation and they're all good."

Nauert flatly denied that Tillerson called Trump a moron. "He did not use that language to speak about the President of the United States," she told reporters. She added that Tillerson made the decision to come before the cameras to address the story. "He was not asked to do this, he knew it was the right thing to do," Nauert said.

White House press secretary Sarah Sanders told reporters on Air Force One that Trump continues to have confidence in Tillerson. If he didn't, she said, Tillerson wouldn't still be in his position.

"He's smart"

Tillerson worked to distance himself from that discord, declaring that reports of his friction with Trump are the "erroneous" product of Washington back-biting that he doesn't indulge in or condone.

The former ExxonMobil CEO went on to offer effusive praise for Trump's approach to the world.

"President Trump's foreign policy goals break the mold of what people traditionally think is achievable by our country," Tillerson said. "Our job is now to achieve results on behalf of America and we are doing that."

"What we have accomplished, we have accomplished as a team," Tillerson said, listing a series of foreign policy steps the administration has taken, including sanctioning North Korea, pressing Arab leaders to do more against terrorism and working with India and Pakistan to stabilize Afghanistan.

Tillerson noted that he didn't know Trump before he accepted the job and had learned about him since then.

"He loves this country. He puts Americans and America First. He's smart," Tillerson said in the hastily arranged statement from the State Department's ornate Treaty Room. "He demands results wherever he goes, and he holds those around him accountable."

But tensions between Tillerson and Trump have been simmering for months, sometimes visibly, as the two have publicly diverged on some of the administration's most crucial foreign policy challenges and the searing domestic tragedy in Charlottesville, VA, when a white supremacist drove a car into a crowd and killed a young woman.

Over the past several months, Trump has been agitated -- but not outright furious -- at the distance Tillerson has put between himself and the White House on issues like Qatar, Charlottesville and North Korea, the source familiar with Trump's thinking said.

Tillerson's pressure on Trump to certify Iran's compliance with the nuclear deal in July made him more upset, but nearly every administration official was on Tillerson's side, making it harder for Trump to fully blame him.

Separately, another official suggested Tillerson will want to help Trump get through his November trip to Asia, an exhausting five-country tour that includes a high-stakes visit to Beijing. Tillerson was in Beijing last week to lay some of the groundwork for those talks.

Trump himself took to twitter after Tillerson spoke, stating: "The @NBCNews story has just been totally refuted by Sec. Tillerson and @VP Pence. It is #FakeNews. They should issue an apology to AMERICA!"

NBC issued a statement saying that it stands by its reporting, which involved speaking to a dozen officials.

Tillerson blamed the reports on Washington back-biting, making clear that he sees himself as an outsider.

"While I'm new to Washington, I have learned that there are some who try to sow dissension to advance their own agenda by tearing others apart, in an effort to undermine President Trump's own agenda," Tillerson said. "I do not and I will not operate that way."

Tillerson expressed frustration that the reports of tension with Trump continue to surface and said he decided to speak publicly to "reaffirm my commitment to this role President Trump has asked me to serve and to dispel this notion that I have ever considered leaving."

He said that he has been asked "repeatedly" if he's going to step down.

"For some reason it continues to be misreported," Tillerson complained. "There's never been a consideration in my mind. I serve at the appointment of the president and I'm here as long as the president feels I can be useful to achieving his objectives."