Rex Tillerson ducks question when asked if he branded Donald Trump ‘a moron’

The strained relationship between President Donald Trump and US secretary of state Rex Tillerson came under renewed focus on Sunday, as the nation’s top diplomat insisted Mr Trump has not undermined him even as he again refused to deny calling the president “a moron”.

Tensions between the two men have grown while the nation faces a series of high-stakes international crises, including the threat posed by North Korea and fate of the Iran nuclear deal, and threatens to sow doubt about American allies as to whether Mr Tillerson can speak authoritatively for the United States.

The secretary of state insisted he has a strong working relationship with the president without any name-calling.

“I call the president ‘Mr. President’, he and I have a very, very open, frank and candid relationship.

“We have a very open exchange of views on policy,” Mr Tillerson said during an interview with Jake Tapper on CNN’s State Of The Union.

“At the end of the day, he makes decisions. I go out and do the best I can to execute those decisions successfully. He has assembled a very, I think, unconventional team,” Mr Tillerson continued.

“He himself is an unconventional president. He’s assembled an unconventional Cabinet. I’m an unconventional pick for secretary of state.”

But Mr Tillerson would not answer repeated questions as to whether he called Mr Trump, as has been reported, “a moron” after a tense meeting at the Pentagon in July during which the national security team stressed to a sceptical president the need for a robust American presence around the globe.

First, Mr Tillerson parried: “I’m not going to deal with that kind of petty stuff.”

Then he stonewalled: “As I said, Jake, I’m not playing.”

Then he side-stepped: “I’m not making a game out of it.”

And then he danced around it: “I’m not dignifying the question with an answer, Jake.”

The firestorm around the “moron” comment, which was first reported by NBC, prompted Mr Tillerson to hold a remarkable press conference at the State Department earlier this month during which he pledged loyalty to Mr Trump but did not deny using the word.

A State Department spokeswoman later denied that Mr Tillerson said it.

But the reports infuriated Mr Trump, who privately bashed his secretary of state to associates and publicly challenged Mr Tillerson to an IQ test.

“And I can tell you who is going to win,” Mr Trump told Forbes magazine.

The White House later said he was joking.

But despite Mr Tillerson’s efforts to move beyond the story, it has created a perception among many in Washington that the clash with Mr Trump has weakened the secretary of state’s voice on the world stage.

Tennessee senator Bob Corker, a Republican who has recently become a vocal critic of the president, last week suggested that Mr Tillerson had been “castrated” by the president.

Mr Tillerson, a ranch owner, joked that he had not been gelded.

“I checked. I’m fully intact,” he said.

The White House did not immediately respond to Mr Tillerson’s interview.

Mr Trump visited his Virginia golf course for the second consecutive day on Sunday.