The interim Ukip leader, Nigel Farage, has waded into the crisis engulfing Donald Trump’s US presidential bid, insisting the Republican candidate’s obscene remarks about groping women amounted to “alpha-male boasting”.

Speaking in St Louis, Missouri, where he is attending this weekend’s televised presidential debate as a Trump supporter, Farage said the comments were “ugly” but that women also made remarks they would not want to see reported.

“Look, this is alpha-male boasting,” he said. “It’s the kind of thing, if we are being honest, that men do. They sit around and have a drink and they talk like this.

“By the way, quite a lot of women say things amongst themselves that they would not want to see on Fox News or the front page of a newspaper. I’m not pretending it’s good – it’s ugly, it is ugly.”

Farage’s comments echo the initial response of Trump who dismissed the obscene language on a 2005 video tape as “locker room banter” before the scale of the crisis overwhelming his presidential campaign forced him to issue an apology.

On the tape, Trump, who was newly married to his third wife, Melania, at the time, talks about making a pass at a married woman, saying: “I moved on her and I failed, I’ll admit it ... I did try and fuck her. I moved on her like a bitch, but I couldn’t get there. And she was married.”

Trump then talks about going after women, saying: “I am automatically attracted to beautiful women. I just start kissing them. It’s like a magnet. Just kiss, I don’t even wait ... and when you’re a star, they let you do it. You can do anything.

“Grab them by the pussy. You can do anything.”

Farage has previously spoken at a Trump rally, and was reported to be helping the Republican candidate prepare for the second presidential debate, after Hillary Clinton was widely seen to have won the first one by a clear margin.

Melania Trump has said she was offended by her husband’s remarks but that they did not represent the man she knew.

“The words my husband used are unacceptable and offensive to me. This does not represent the man that I know. He has the heart and mind of a leader,” she said.

Trump has insisted there is “zero chance” he will quit the race for the White House after the comments provoked a firestorm of outrage.

He has been branded “the groper in chief” on social media, “horrific” by Hillary Clinton and “sickening” by the Republican speaker of the US house of representatives, Paul Ryan.