The public conflict showed no signs of slowing, as Manigault Newman did another round of interviews to promote her tell-all book and Trump's presidential campaign filed arbitration action against her alleging she breached a confidentiality agreement.

Manigault Newman, who has painted a damning picture of Trump and alleged there is a videotape of him using a racial slur, told The Associated Press she is not going away.

"I will not be silenced. I will not be intimidated. And I'm not going to be bullied by Donald Trump," she said.

Trump, who has denied the existence of any such tape, assailed Manigault Newman in language that stood out even by his trash-talking standards, praising his chief of staff, John Kelly, "for quickly firing that dog!" That slam follows a pattern of inflammatory language about women and minorities.

During the 2016 campaign, Trump described Huffington Post founder Arianna Huffington as "a dog." He has recently targeted California Rep. Maxine Waters, basketball star LeBron James and TV journalist Don Lemon, all African-Americans, and has repeatedly attacked black football players for kneeling during the national anthem in social protest.

Manigault Newman told the AP that "at every single opportunity he insults African-Americans," and she accused him of trying to start a "race war."

During the campaign and her White House tenure, Manigault Newman, who was the highest ranking black official in the West Wing, stood by Trump even at moments of racial strife, including the clashes between white supremacists and counterprotesters in Charlottesville, Virginia, and Trump's targeting of NFL players kneeling during the national anthem in social protest.

Fired by Kelly in December, Manigault Newman now says many of Trump's actions gave her pause but she was sympathetic to him as a longtime friend and mentor.

In her book, she casts herself as a strong black woman who overcame humble beginnings and has often navigated hostile work environments with aplomb.

Now she is aligning herself with Trump's victims, said Leah Wright Rigueur, a historian at Harvard's Kennedy School of Government.

"She's drawing a direct line of comparison between herself and other black women Trump has attacked," Rigueur said. "She's suggesting that the president is racist and sexist and using herself as evidence."

White House spokeswoman Sarah Huckabee Sanders insisted yesterday that the president's insults were not racially motivated, saying: "This has absolutely nothing to do with race and everything to do with the president calling out someone's integrity."

A contestant on the first season of Trump's TV show "The Apprentice" and a veteran of reality television, Manigault Newman has managed her explosive book tour for maximum effect, conducting back-to-back interviews and teasing out new bits of information in each one, successfully baiting the television-watching president.

Central to her argument that Trump is racist is her claim that she had heard an audiotape of him using the N-word.

Trump has pushed back hard, tweeting that he had received a call from the producer of "The Apprentice" assuring him "there are NO TAPES of the Apprentice where I used such a terrible and disgusting word as attributed by Wacky and Deranged Omarosa."

White House spokeswoman Sarah Sanders said she could not guarantee Trump had never used a racial slur. Asked if she could say with certainty that Trump had never used the N-word, she said: "I haven't been in every single room," though she stressed that the president has addressed the question and denied ever using such language.

Manigault Newman continued to stir the pot yesterday, providing CBS another audio recording that she said showed campaign workers discussing the alleged recording.

Her allegations put Trump allies on their heels and clearly got under the president's skin.

Trump insisted, "I don't have that word in my vocabulary, and never have." He said Manigault Newman had called him "a true champion of civil rights" until she was fired.

Manigault Newman writes in her book that she'd heard such tapes of Trump language existed. She said Sunday that she had listened to one after the book closed.

Asked if the book can be backed up by email or recordings, Manigault Newman said on CBS that every quote in the book "can be verified, corroborated and it's well documented," suggesting she may have more information to release.

She told the AP that she's been interviewed by special counsel Robert Mueller's team investigating Russian election interference, though she did not provide any details. A person familiar with the White House response to the investigation said that at no time prior to her departure did the Mueller team request documents related to her or seek an interview with her. The person insisted on anonymity to discuss the investigation.

Manigault Newman also asserted on MSNBC that Trump knew in advance about the release of Hillary Clinton's emails by WikiLeaks, but did not provide any evidence.