First lady Michelle Obama has scathingly condemned Donald Trump, calling his boasts about groping women 'shocking and demeaning'.
Mrs Obama's voice cracked with emotion during a campaign speech for Democratic nominee Hillary Clinton in New Hampshire.
She said seeing Mr Trump make lewd comments about women, on a video leaked last week to the Washington Post, "has shaken me to my core in a way that I cannot have predicted".
In the recording Mr Trump boasted that his fame meant he could "do anything" to women.
Mrs Obama said this attitude was "cruel" and "frightening".
"This is not normal. This is not politics as usual," Mrs Obama said.
"This is disgraceful. It is intolerable. It doesn't matter what party you belong to - Democrat, Republican, independent. No woman deserves to be treated this way."
Since the video emerged, The New York Times has reported that two women endured sexual aggression from the Republican presidential candidate.
However, Mr Trump has denied these and other accusations of sexual assault, calling the claims 'pure fiction'.
One woman, Jessica Leeds, appeared on camera on The New York Times' website to recount how Mr Trump grabbed her breasts and tried to put his hand up her skirt on a flight from the Midwest to New York in or around 1980.
The second woman, Rachel Crooks, described how Mr Trump "kissed me directly on the mouth" in an unwanted advance in 2005 outside the elevator in Trump Tower in Manhattan, where she was a receptionist at a real estate firm.
Within hours of The New York Times report, several other media outlets published similar reports. People magazine published a detailed first-person account from one of its reporters, Natasha Stoynoff.
Stoynoff said Mr Trump pinned her against a wall at his Florida estate in 2005 and kissed her as she struggled to get away.
"I turned around, and within seconds, he was pushing me against the wall, and forcing his tongue down my throat," Stoynoff said.
Mr Trump, 70, denied the People story in a Twitter message and mocked the writer in a speech in Florida.
"I ask her a simple question. Why wasn't it part of the story that appeared 12 years ago.
"Why didn't they make it part of the story ... if she had added that it would have been the headline."
"Look at her and look at her words," he said. "You tell me what you think. I don't think so."
The Palm Beach Post reported a claim by South Florida woman Mindy McGillivray, 36, that Mr Trump had grabbed her bottom 13 years ago while she was working at his Mar-a-Lago estate as a photographer's assistant.
"There is no truth to this whatsoever," Mr Trump's spokeswoman, Hope Hicks, told the Post.
McGillivray could not be reached for comment.
'These claims are all fabricated' - Trump
Democratic rival Hillary Clinton, The New York Times and other media were engaged in a concerted, "vicious" attempt to stop him, Mr Trump told a rally in Florida.
"These claims are all fabricated. They're pure fiction and they're outright lies. These events never, ever happened," Mr Trump said.
He would make evidence public to dispute the claims at some point, he said.
"These vicious claims about me of inappropriate conduct with women are totally and absolutely false. And the Clintons know it and they know well."
Mr Trump's campaign has demanded the newspaper retract the story, calling it libelous, and threatening legal action if it did not comply.
"This entire article is fiction, and for The New York Times to launch a completely false, coordinated character assassination against Mr Trump on a topic like this is dangerous," the Trump campaign's senior communications adviser, Jason Miller, said in a statement.
The New York Times said it stands by the story, and rejected claims the article was libelous.
Assistant general counsel for the newspaper, David McCraw, said in a letter to Mr Trump's lawyers: "we welcome the opportunity to have a court set him straight".
Reuters could not independently verify the incidents as Leeds and Crooks did not respond to requests for comment.
Trump's campaign was already struggling to contain a crisis after a video surfaced last week showing him bragging in 2005 about groping women and making unwanted sexual advances.
A spokeswoman for Mrs Clinton, 68, said Wednesday's report in The New York Times was "disturbing."
"These reports suggest that he lied on the debate stage and that the disgusting behavior he bragged about in the tape is more than just words," spokeswoman Jennifer Palmieri said.
Trump lagging in the polls
The Times report came just two days after a Reuters/Ipsos opinion poll showed one in five Republicans thought Mr Trump's comments about groping women disqualified him from the presidency. The poll also showed him 8 points behind Mrs Clinton among likely voters.
Mr Trump, a New York businessman and former reality TV star, has never previously run for political office. Controversy has stalked his White House campaign since the day in June 2015 when he announced he was running for president, describing Mexican immigrants as rapists and criminals in a speech.
Establishment Republicans have struggled to get behind Mr Trump, alarmed by both his style and some of his policy proposals.
-Reuters / BBC