Rexit? Rex Tillerson 'to quit as Donald Trump's secretary of state before the end of the year'

US Secretary of State Rex Tillerson is growing increasingly disillusioned with President Donald Trump and could leave his administration before the end of the year, according to two sources who spoke to CNN.

Mr Tillerson has found himself undermined by the president, who openly contradicts him and appears disinterested in the work of Mr Tillerson's team of career diplomats at the state department.

Friends of Mr Tillerson's had previously believed he would ride out the rollercoaster at Foggy Bottom - home of the state department. But CNN on Monday reported that the friends had noticed "a change in tone," and thought that he could well be planning on leaving Washington.

"His frustration is hardly a secret and it has spilled out publicly at times," CNN reported. 

"But friends sense a change of late.

"Two sources who spoke to CNN on condition of anonymity over the weekend said they would not be surprised if there was a 'Rexit' from Foggy Bottom sooner that that."

The 65-year-old Texan has made no secret of his struggle with the role.

Reluctant in front of the camera, in his first interview he said he had only taken the job because his wife thought it was a good idea.

The president has made his life harder by blocking a number of people Mr Tillerson wished to appoint, including  stopping the hiring of Elliott Abrams as Mr Tillerson's second in command, because Mr Abrams was critical of Mr Trump and his policy positions during the 2016 campaign.

The state department is described as a hollowed-out and demoralised institution under Mr Tillerson, who has failed to convince his boss that diplomacy is something to be prized.

Mr Tillerson reportedly got involved in a heated argument about staffing, in which Jared Kushner, the president's son-in-law and senior adviser, reportedly called Mr Tillerson "unprofessional".

During his tirade, inside the office of chief of staff Reince Priebus, Mr Tillerson reportedly quarreled with the director of presidential personnel, Johnny DeStefano, and made clear he didn’t want the White House to “have any role in staffing.”

Mr Tillerson has also been undermined on policy.

He advocated remaining neutral during the Gulf dispute with Qatar, saying: “We call on the Kingdom of Saudi Arabia, the United Arab Emirates, Bahrain, and Egypt to ease the blockade against Qatar. There are humanitarian consequences to this blockade."

Hours later, Mr Trump went against his position and openly backed Saudi Arabia.

“The nation of Qatar, unfortunately has historically been a funder of terrorism at a very high level,” said Mr Trump. “And in the wake of that conference, nations came together and spoke to me about confronting Qatar over its behaviour."

Mr Tillerson unsuccessfully argued against Mr Trump pulling the US out of the Paris climate change agreement, and when asked whether he still wishes the US was part of the deal, he replied: "My views haven't changed."

In June The New York Times spoke to three ambassadors – two in Europe, one in Asia – who said they were so muddled by the lack of leadership from the state department that they had taken to referring their inquiries to the national security council instead.

Were Mr Tillerson to resign, he would be far from the shortest-tenured secretary of state.

Elihu Washburne only served 11 days under Ulysses Grant, before being made ambassador to France.