Melania Trump said in a TV interview that she loves President Donald Trump and has "much more important things to think about" than allegations he cheated on her with a porn star, a Playboy Playmate or anyone else.

Key points: Mr Trump has been accused of having multiple affairs

Mr Trump has been accused of having multiple affairs Porn star Stormy Daniels and ex-Playboy Playmate Karen McDougal have said they had sex with him years ago

Porn star Stormy Daniels and ex-Playboy Playmate Karen McDougal have said they had sex with him years ago First lady plays down a suggestion the rumours of her husband's philandering had strained their marriage

Mrs Trump, who was interviewed by US network ABC while touring Africa last week, said people are just spreading rumours about her marriage.

"I know people like to speculate and media like to speculate about our marriage and circulate the gossip," she said.

"But I understand the gossip sells newspapers, magazines … and, unfortunately, we live in this kind of world today."

She insisted allegations of her husband's infidelities were not a concern.

Mr Trump, who during the 2016 presidential campaign was heard on an old Access Hollywood tape talking about groping and trying to have sex with women, has been accused of having multiple affairs.

Porn star Stormy Daniels and ex-Playboy Playmate Karen McDougal have said they had sex with him years ago.

Stormy Daniels, whose real name is Stephanie Clifford, said she had sex with Donald Trump years ago. ( AP: Matt Sayles )

Mr Trump has denied the trysts with Ms Daniels and Ms McDougal but has acknowledged reimbursing his lawyer for a $US130,000 hush money payment to Ms Daniels.

Mrs Trump has generally kept quiet on the subject.

Asked in the interview if she loves her husband, Mrs Trump said, "Yes, we are fine. Yes."

She played down a suggestion the repeated rumours of his philandering had put a strain on their marriage.

"It is not concern and focus of mine," she said.

"I'm a mother and a first lady, and I have much more important things to think about and to do."

But when asked if the repeated rumours had hurt her, she paused.

Then she reiterated the "media world is speculating".

"Yeah, it's not always pleasant, of course," she said. "But I know what is right and what is wrong and what is true and not true."

Parts of Mrs Trump's interview aired on Friday on Good Morning America.

ABC America aired more from the interview during a hour-long special broadcast Friday night, during which Mrs Trump explained why she wore a jacket that said "I really don't care, do u?" on a trip to the border to visit migrant children who had been separated from their parents.

She noted that she wore the jacket getting on and off the plane, but not during her visits with children, and said it was a message to "people and the left-wing media who are criticising me".

US first lady Melania Trump was questioned about her husband's alleged cheating. ( Reuters: Carlo Allegri )

Mrs Trump said the jacket was a statement that the criticism will not stop her from doing "what I feel is right".

She said she deliberately wore the jacket on the flight back to Washington after seeing "how the media was obsessed about it".

"It was kind of a message, yes," the first lady said.

In another part of the interview, which aired earlier this week, Mrs Trump said she could be "the most bullied person" in the world and women who make accusations of sexual assault need to "show the evidence".

On an Access Hollywood tape from 2005 that became public during the 2016 campaign, Mr Trump said when he's attracted to beautiful women, "I just start kissing them. It's like a magnet."

"Grab them by the p----," he said. "You can do anything."

Mr Trump's former personal lawyer Michael Cohen pleaded guilty in August to campaign finance violations alleging he, Mr Trump and the National Enquirer tabloid were involved in buying the silence of Ms Daniels and Ms McDougal after the alleged affairs.

AP