It was reported by the Washington Post that Mr Tillerson was informed of his dismissal several days ago. However, the timing of the announcement, which followed the White House’s refusal to echo Theresa May’s accusation against Moscow, risks isolating Downing Street.
The US President tweeted that the CIA Director Mike Pompeo would take over at the State Department.
There had been longstanding rumors to friction between the President and Mr Tillerson, a former Exxon Mobile chief executive. The Secretary of State had previously been forced to deny media reports that he called Mr Trump a “moron”.
On Monday, Mr Tillerson had echoed the Prime Minister’s comments about Moscow’s involvement in the Salisbury attack, saying it “clearly came from Russia”.
White House Press Secretary Sarah Sanders had earlier condemned the attack in a briefing to reporters, but stopped short of laying the blame for the attack at the door of the Kremlin.
Under Mr Tillerson, however, the State Department issued their own strongly-worded statement condemning Russia’s actions and pledging support to the UK.
British officials will now be understandably anxious about the prospect of a new direction on Russia from President Trump, who has been far softer on Vladimir Putin’s regime than previous White House incumbents.
US outlets are reporting Mr asked Mr Tillerson to resign his post on Friday, when the two disagreed on the President’s plans to meet North Korean dictator Kim-Jong-Un.
Mr Tillerson’s statement yesterday on Russia’s suspected role in the attack in Salisbury incident, which has left Sergei Skripal and his daughter in a critical condition, surprised observers.
It is possibly more forceful as a result of his imminent departure, rather than the cause of it.
Mr Tillerson’s dismissal continues a whirlwind staffing approach from Mr Trump, with departures from senior roles taking place on an almost monthly basis since his inauguration.
The now former Secretary of State joins a list of White House departures that include a Press Secretary, a National Security Adviser, three Communications Directors, a Chief of Staff, and a Chief Strategist.