Daniels' appearance represented back-to-back trouble for Trump after an interview broadcast last week on CNN with former Playboy model Karen McDougal, who described a 10-month long affair with Trump starting in 2006.

Trump would have been married to his wife, Melania, during both the alleged extramarital relationships. The first lady accompanied him this weekend to his Florida golf club. Trump returned to the White House on Sunday but a White House spokeswoman said Melania stayed behind as is her tradition during their son's school holiday.

Not attracted

Daniels told 60 Minutes that she and Trump had had sexual relations only once, but that she had seen him on other occasions and he had kept in touch with her.

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She said she was not attracted to Trump, who was 60 in 2006 when she was 27.

The White House has denied he had an affair with Daniels, although Trump lawyer Michael Cohen said he paid her $US130,000 of his own money during the 2016 presidential election campaign.

Trump did not respond to reporters' shouted questions about whether he would watch the interview when he returned to the White House from Florida.

Cohen, who has denied that there was an affair, has not explained why he made the payment nor said whether Trump was aware of it.

Daniels and her attorney would not discuss in the interview whether they had text messages or other materials that might verify her story.

She was asked why she repeatedly signed statements denying the relationship with Trump, and acknowledged that there could be questions about her credibility.

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"I felt intimidated and ... honestly bullied. And I didn't know what to do. And so I signed it," Daniels said.

Asked why viewers could be confident now that she was telling the truth, she said, "Because I have no reason to lie. I'm opening myself up for, you know, possible danger, and definitely a whole lot of shit."

Trump's silence now marks a stark contrast to his combative rhetoric in the campaign's closing days, when he threatened to sue more than a dozen women who accused him of sexual misconduct and called them liars.

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Trump did not take any of the women to court, but one of them, former Apprentice contestant Summer Zervos, is suing him for defamation.

His lawyers say Daniels has breached the confidentiality agreement that she signed 11 days before the November 2016 election in return for the $US130,000.

As Daniels seeks a court order voiding the pact, Trump's lawyers are moving to get the lawsuit dismissed. They are trying to force Daniels to go to secret arbitration proceedings, as the agreement required, and pay as much as $US20 million in damages to Trump.

Her 60 Minutes interview could increase the amount; the contract requires Daniels to pay Trump $US1 million each time she violates its terms.

Daniels' attorney, Michael Avenatti, cautioned Trump and his lawyers last week to be "very, very careful" in responding to Daniels' comments to CBS.

He tweeted a photograph of a DVD, telling CNN it was a "warning shot" putting the Trump legal team on notice that it contains evidence substantiating Daniels' relationship with Trump.

"The 60 Minutes interview is not the end by any stretch of the imagination," Avenatti said.