Donald Trump’s National Security Council has even fewer familiar faces following the third forced resignation in less than four months.

Deputy national security adviser KT McFarland has been asked to step down and will become US ambassador to Singapore, as reported by Bloomberg.

The departure of the 65-year-old former Fox News host, who said in an interview that Hillary Clinton was so worried about her Senate candidacy in 2006 that she sent helicopters to her house, comes after two other high-profile moves.

Stephen Bannon, Mr Trump’s chief strategist who appointed himself as a permanent member of the council, was asked to leave this month.

Reports circulated that Mr Bannon, former executive at right-wing platform Breitbart, was being pushed out after failing to implement his two key proposals – the Muslim travel ban and the disastrous failure of the Obamacare replacement plan. He has also reportedly experienced a widening rift with Mr Trump’s trusted son-in-law and senior adviser, Jared Kushner.

Michael Flynn, the former national security adviser and above Ms McFarland, was forced to resign in February after he misled Vice President Mike Pence about his phone calls with the Russian ambassador.

The shake-up came as Lieutenant General H R McMaster replaced Mr Flynn and set about reorganising the council over the past two months.

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Dina Powell is still the deputy national security adviser, and has an office very close to Ivanka Trump.

The NSC section of the White House website is blank, saying: “Check back soon for more information”.

Government critics have praised the departure of Ms McFarland, describing her as a “crony” of Mr Flynn.

Prior to her appointment in February, she worked under several other administrations including Gerald Ford and Richard Nixon, and has had more experience than some of her colleagues. She was condemned, however, for peddling conspiracy theories and engaging in Islamophobic rhetoric.