DONALD Trump has fired US Secretary of State Rex Tillerson and replaced him with CIA director Mike Pompeo.

The US president said Gina Haspel will become the new CIA director, the first woman chosen for the job.

Trump tweeted that Pompeo, "will do a fantastic job!" and thanked Tillerson for his service.

He said he made the decision to sack his secretary of state "by myself" and that Tillerson will be "much happier now".

At 9.15am, Trump left the White House for a visit to California, to see prototypes for his border wall. Pausing by the Marine One helicopter to talk to reporters, he said he had been “talking about this for a long time”.

“I’ll be speaking to Rex over a long period of time,” Trump said. “I actually got on well with Rex but it was a different mindset.”

He and Tillerson had “disagreed on things”, he said, including “the Iran deal... So we were not thinking the same. With Mike Pompeo, we have a similar thought process.”

A senior State Department official said Trump never explained to Tillerson the reason why he was fired.

The undersecretary of state for public diplomacy, Steve Goldstein, said Tillerson "had every intention of staying" in the job because he felt he was making critical progress in national security.

Two White House officials have said Tillerson was told he was out on Friday, but Goldstein said he "did not speak to the president and is unaware of the reason".

Tillerson had returned from a shortened trip to Africa hours before Trump's announcement, which offered no explanation for the change.

A White House official said Trump wanted to have a new team in place before upcoming talks with North Korea and various trade negotiations.

There had been rumours throughout most of Tillerson's tenure of friction between Trump and his secretary of state, a former ExxonMobile chief executive.

In October, NBC news reported that Tillerson called the president a "moron," something he never actually denied.

Tillerson continued to insist his relationship with the president was solid and brushed off rumours of strain between them.

Professor Phillips O’Brien, Chair in Strategic Studies at the University of St Andrews, gave his opinion on the latest move from Trump.

He stated: “The firing of Secretary of State Tillerson in on the one hand predictable within Donald Trump’s world, and at the same time another sign of the president’s growing isolation and inability to listen to messages that he does not want to hear. Tillerson was definitely not a Trump insider, and was selected by Trump to reassure the world and mainstream Republicans that he would not disrupt many of the traditional tenets of Republican foreign policy. However, as an outsider with cautious instincts, it was clear from the start that Tillerson was not particularly influential in the White House and his influence over US foreign relations was relatively muted.

By replacing him, however, Trump continues a very worrying trend of getting rid of people who provide advice he does not want to hear. It is telling that just a few hours ago, Tillerson blasted the Russian government for its involvement in the assassination attempt on Sergei Skripal, while at the same time the White House refused to admit that the Russians might have been involved in the attempted murder.

The replacement of Tillerson by Mike Pompeo shows that Trump will continue to shore up his base at the expense of reaching out to more mainstream Republicans. A Kansas congress member with Tea Party roots, Pompeo is known to be much closer to Trump politically and personally, and more in tune with the president’s base. It will be telling if the new secretary of state begins to walk back from his predecessor’s criticisms of Russia.”

Tillerson was due to retire from Exxon in March 2017 aged 65 under the company's mandatory retirement policy.

Tillerson was paid 27.3 million dollars (£19.5 million) last year, and has accumulated roughly 160 million dollars (£115 million) in Exxon stock along with 149 million dollars (£107 million) of unvested stock options.