Former White House aide Omarosa Manigault Newman has said she will not be silenced by US President Donald Trump.

The former contestant on Mr Trump’s hit reality TV show The Apprentice remained defiant as her public feud with her ex-boss threatens to move into the courtroom.

Ms Manigault Newman, who is promoting her new book about her time in Mr Trump’s orbit, told the Associated Press she believes the president’s campaign organisation is trying to keep her from telling her story.

She commented just hours after Mr Trump’s campaign announced it was filing an arbitration action against her, alleging that she violated a secrecy agreement.

“I will not be intimidated,” she said. “I’m not going to be bullied by Donald Trump.”

Still, the former reality TV star-turned-political aide declined to answer several questions about her experiences during her year as the highest-ranking African-American aide in Mr Trump’s White House, citing the arbitration action.

She also declined to discuss details of her interview with special counsel Robert Mueller’s office.

But Ms Manigault Newman continued to unleash scathing criticism of Mr Trump, saying he is unfit to be president. She accused him of using his rowdy political rallies to sow racial division and even suggested Mr Trump is promoting violence.

Discussing the differences between their views, she said: “One, I want to see this nation united as opposed to divided. I don’t want to see a race war as Donald Trump does.”

Omarosa Manigault Newman
Ms Manigault Newman came under stinging criticism after releasing audio recordings (AP)

The White House said Ms Manigault Newman has “shown a complete lack of integrity” with her criticism of Mr Trump in her book.

Press secretary Sarah Huckabee Sanders said that Mr Trump’s tweets referring to Ms Manigault Newman as “crazed” and a “dog” reflect his “frustration” with her comments. Ms Manigault Newman responded that Mr Trump has “absolutely no respect” for women or African-Americans.

Ms Sanders says Mr Trump hired Ms Manigault Newman as an assistant to the president because he “wanted to give her a chance”.

Ms Manigault Newman has been releasing audio recordings of private White House conversations as part of her book roll-out tour. She was fired in December.

She said the president’s proclivity for racial division is evident “when you see at every single opportunity he insults African-Americans”.

She noted, as examples, Mr Trump’s recent criticism of NBA player LeBron James and California Democratic representative Maxine Waters.

Mr Trump recently tweeted that it took the “dumbest man on television” — also an African-American — to make James “look smart”, and he regularly refers to Waters as “low IQ.”

Donald Trump
Ms Manigault Newman is releasing a tell-all book about Mr Trump (AP)

“He wants to divide this nation,” said Ms Manigault Newman, speaking during the publicity tour for her book, Unhinged, in which she portrays Mr Trump as racist and misogynistic.

“He wants to pit his base against successful African-Americans,” she said. “He uses his rallies to really encourage people to bring down African-Americans. That is truly evidence that this man is not trying to unite us. But he is specifically trying to divide us.”

Asked how Mr Trump would benefit from a racially divided nation, Ms Manigault Newman said to ask the president.