Donald Trump has lashed out at former White House adviser Omarosa Manigault Newman, calling her “wacky” and saying she had been “fired for the last time” after she released audio recordings purportedly of the US president.

Mr Trump tweeted that his chief of staff John Kelly had called Ms Manigault Newman a “loser & nothing but problems”.

He added: “I told him to try working it out, if possible, because she only said GREAT things about me – until she got fired!”

Mr Trump’s retaliation came after Ms Manigault Newman, who is promoting a tell-all book, released another recording to the media.

Aired on NBC’s Today show, it is said to be an excerpt of a phone conversation between her and Mr Trump after she was fired from the White House. It appears to show Mr Trump expressing surprise, saying: “Nobody even told me about it.”

Ms Manigault Newman told NBC’s Meet the Press that she surreptitiously recorded a number of conversations in the White House for her own protection. The show aired portions of a recording of her sacking by Mr Kelly in the high-security Situation Room.

Critics have denounced the recordings as a serious breach of ethics and security. The voice on the recording released seems to be Mr Trump’s.

Mr Trump acknowledged Monday that the president of the United States should perhaps not engage in a public war of words with an ex-employee, saying he knows it is “not presidential” to take on “a lowlife like Omarosa”.

But he added: “This is a modern day form of communication and I know the Fake News Media will be working overtime to make even Wacky Omarosa look legitimate as possible. Sorry!”

Responding to Mr Trump’s tweets on NBC, Ms Manigault Newman said: “I think it’s sad that with all the things that’s going on in the country that he would take time out to insult me and to insult my intelligence.”

Omarosa Manigault Newman
The White House has referred to Ms Manigault Newman as a ‘disgruntled ex-employee’ (AP)

She added: “This is his pattern with African-Americans.”

While the latest recording has Mr Trump indicating he was unaware of her sacking, Ms Manigault Newman said on Today that he may have instructed Mr Kelly to carry it out.

White House spokesman Hogan Gidley said: “I’m not going to get into the tick-tock of who knew what when, but the president makes the decisions.”

Ms Manigault Newman, whose book Unhinged is out this week, suggested there was more to come: “There’s a lot of very corrupt things happening in the White House, and I am going to blow the whistle on a lot of them.”

Donald Trump’s attorney, Rudy Giuliani, said on Fox and Friends that Ms Manigault Newman may have broken the law by recording private conversations inside the White House.

“She’s certainly violating national security regulations, which I think have the force of law,” he said.

In the recording with Mr Kelly, which Ms Manigault Newman quotes extensively in her new book, Mr Kelly can be heard saying that he wants to talk with her about leaving the White House.

“It’s come to my attention over the last few months that there’s been some pretty, in my opinion, significant integrity issues related to you,” he is heard saying, citing her use of government vehicles and “money issues and other things” that he compares to offences that could lead to a court-martial in the military.

Donald Trump
Donald Trump has referred to Ms Manigault Newman as a ‘lowlife’ (AP)

He adds: “If we make this a friendly departure … you can look at your time here in the White House as a year of service to the nation and then you can go on without any type of difficulty in the future relative to your reputation.

“There are some serious legal issues that have been violated and you’re open to some legal action that we hope, we think, we can control.”

Ms Manigault Newman said she viewed the conversation as a “threat” and defended her decision to covertly record it and other White House conversations.

“If I didn’t have these recordings, no one in America would believe me,” she said.

White House press secretary Sarah Huckabee Sanders said: “The very idea a staff member would sneak a recording device into the White House Situation Room, shows a blatant disregard for our national security – and then to brag about it on national television further proves the lack of character and integrity of this disgruntled former White House employee.”

The Situation Room is a sensitive compartmented information facility (SCIF), where the nation’s most consequential foreign policy decisions are made, and staff are not permitted to bring in cellphones or other recording devices.

Ned Price, who served as spokesman of the National Security Council in the Obama administration, said: “I’ve never heard of a more serious breach of protocol.

Sarah Huckabee Sanders
White House press secretary Sarah Huckabee Sanders was scathing over the former presidential aide’s claims (AP)

“Not only is it not typical, something like this is unprecedented.”

Mr Price said there is no-one checking staffers for devices at the door, but there is a sign outside the room making it clear that electronic devices are prohibited.

In the book, Ms Manigault Newman paints a damning picture of Mr Trump, including claims that tapes exist of him using the N-word as he filmed his reality series The Apprentice, which she co-starred in.

The White House had previously tried to discredit the book, with Ms Sanders calling it “riddled with lies and false accusations”.

Ms Manigault Newman had been a staunch defender of the president for years, and, as the highest-profile African-American in the White House, had hit back at accusations that he was racist.

She now said she was “used” by Mr Trump, calling him a “con” who “has been masquerading as someone who is actually open to engaging with diverse communities” and is “truly a racist”.

“I was complicit with this White House deceiving this nation,” she said. “I had a blind spot where it came to Donald Trump.”