New book reveals how Melania Trump reacted to Donald's 'grab 'em by the p****' tape

A new book about Melania Trump written by one of her former closest friends has shed new light on the most jaw-dropping moment of the 2016 US election.

Melania & Me: The Rise and Fall of My Friendship with The First Lady, penned by event planner Stephanie Winston Wolkoff, gives an unfavourable glimpse into the mechanics of the Trump family - and particularly at Melania.

The book has already come under fire from the Trump administration, who say Winston Wolkoff made secret illegal recordings of conversations with Melania - but the author has defended the biography, and is adamant everything in it is true.

One particularly notable excerpt describes Melania's surprising reaction to an infamous Access Hollywood tape, in which her husband was secretly recorded making lewd comments about women.

"I don't even wait," Trump can be heard saying on the tape. "And when you're a star, they let you do it. You can do anything... Grab 'em by the p***y. You can do anything."

In an interview with breakfast talk show Good Morning America to publicise the book, Winston Wolkoff described meeting Melania for lunch just after the video footage had been leaked to the media.

"Now if any other human being or any other one of my friends [had gone through this], I would have expected to see them in tears, right?" she said.

"[But] she was smiling. It was as if nothing had happened. And I swear to you, I had like a glitch in my brain; I was like, 'Is this really happening at this moment? Is it surreal that her husband just came out and said these horrible things?'

"I said to her, 'How many times have you heard the words p***y and president in the same sentence?' And then we burst out laughing.

"Then I said to her, 'Are you upset? Doesn't this get you angry, that Donald would say something like this?' And Melania's a pragmatist - you know, 'If you can't control people's emotions, then why even worry about it?'

"That's how she lived her life. That is what she stood by every day."

Winston Wolkoff explains her and Melania's friendship came to an end after Donald's inauguration as US President, which her event planning company was contracted to pull together.

The inauguration soon became the subject of a federal investigation over misused funds, and Winston Wolkoff felt she was being used as a scapegoat.

She told Good Morning America only US$1.62 million went to her company, when reports had suggested it earned as much as US$26 million - and she was disappointed that Melania never defended her publicly.

"When the time came for her to come and speak the truth about a friend who left everything behind to help her, she turned her back on me, stabbed me in the back," she told Good Morning America.

"I gave Melania the benefit of the doubt that she was my friend - she was different than Donald was, she was different from the other Trump children.

"[Now] a Trump is a Trump is a Trump... The Melania I first met versus the Melania there is today is a very different person."