Trump's statement shook me to my core: Michelle Obama slams Donald Trump

​Washington: US first lady Michelle Obama has urged all Americans to say "enough is enough" to Republican presidential nominee Donald Trump's "intolerable" treatment of women, as "this is not normal and cannot be ignored".

"This wasn't just locker room banter, this was a powerful individual speaking freely and openly about sexually predatory behaviour," Obama said on Thursday at a campaign rally for Democratic presidential nominee Hillary Clinton at Southern New Hampshire University in Manchester, New Hampshire, Efe news reported.

"Enough is enough, this has got to stop right now," the first lady said, adding that Trump's comments have "shaken me to my core in a way that I couldn't have predicted."

"It is not politics as usual. This is disgraceful. It is intolerable," she added.

Obama admitted at the rally that since the release on last Friday of a 2005 videotape on which Trump can be heard making lewd and sexist comments about women, she had been unable to stop thinking about the fact that a candidate for president had bragged about sexually assaulting women.

"The men in my life do not talk about women like this," she said. "This is not how decent human beings behave and this is certainly not how someone who wants to be president of the US behaves."

Trump has called his comments on the videotape "locker room talk" and has issued heated denials of claims by several women that he sexually assaulted them, as reported by The New York Times and People magazine, calling the stories politically-motivated and threatening to file a defamation suit against the Times.

"The phony story in the failing @nytimes is a TOTAL FABRICATION," the billionaire said on Twitter.