A former aide to Donald Trump said on Sunday she secretly recorded her sacking by John Kelly, the chief of staff, in the high-security White House situation room.

Omarosa Manigault Newman also claimed that Americans were being kept in the dark about the US president’s mental decline, saying: “I was complicit with the White House deceiving this nation.”

Miss Newman, whose tell-all book about her White House tenure is released on Tuesday, left the administration in December and says she was threatened by Mr Kelly who told her things could get “ugly” if she did not go on friendly terms.

She also described the president as a racist – an accusation he has repeatedly denied – on the day white nationalists and counter-protesters gathered in Washington to stage rallies on the anniversary of the Charlottesville far-Right march, which left a woman dead.

Miss Newman made the disclosures on US television hours after the president responded to a question about her book "Unhinged: An Insider’s Account of the Trump White House" by saying: “Lowlife. She’s a low life.” The former star of The Apprentice star told NBC’s Meet the Press that she regretted her White House role.