WASHINGTON • United States President Donald Trump firmly denied yesterday that Mr Rex Tillerson had threatened to resign, after a news report said the Secretary of State had called him a moron and had to be repeatedly persuaded not to leave the administration.

"Rex Tillerson never threatened to resign," Mr Trump said in his most direct refutation of the resignation report. "This is Fake News put out by @NBCNews. Low news and reporting standards. No verification from me."

Long-simmering tensions within Mr Trump's national security team spilt into public view on Wednesday, as Mr Tillerson took the extraordinary step of calling a news conference to affirm his support for the President, despite what associates describe as his deep frustration with Mr Trump and talk of resignation.

Mr Tillerson praised Mr Trump but did not deny a report that he once referred to the President as a "moron". Mr Trump welcomed Mr Tillerson's statement of support and declared "total confidence" in his Secretary of State.

If Mr Tillerson had hoped to douse questions about how long he will stay, he instead further fuelled a debate about his future.

Although he insisted he had never considered resigning, several people close to him said he has had to be talked out of drafting a letter of resignation on more than one occasion by his closest allies, Defence Secretary Jim Mattis and White House Chief of Staff John Kelly. They also said he has regularly expressed astonishment at how little Mr Trump understands the basics of foreign policy.

A former chief executive of ExxonMobil, Mr Tillerson has never found his place as a subordinate to the hard-charging, unpredictable President. He has bristled at being undercut, as he was over the weekend when Mr Trump publicly said Mr Tillerson was "wasting his time" by trying to open talks with North Korea.

Yet Mr Tillerson felt compelled on Wednesday to address the internal schism after NBC News reported that he had been prepared to step down this summer until he was talked out of it. "There's never been a consideration in my mind to leave," he said.

Mr Trump has lost a chief of staff, a national security adviser, a chief strategist, a press secretary and two communications directors. He has fired the Federal Bureau of Investigation director, belittled his Attorney-General and publicly assailed the Deputy Attorney-General. And just last week, Mr Tom Price resigned as secretary of health and human services.

That turnover is a reason Mr Trump has not pushed Mr Tillerson out, according to advisers.

REUTERS, NYTIMES