US President Donald Trump has offered an apology for retweeting inflammatory videos by the far-right Britain First group.

In an interview with ITV's Good Morning Britain, Mr Trump said he had known nothing about the organisation when he made the social media postings.

He told interviewer Piers Morgan that he believed the videos showed "radical Islamic terror", but if it was the case that they had been produced by "horrible racist people", then he "would certainly apologise".

Mr Trump caused outrage in the UK when he posted the three tweets last November, prompting Prime Minister Theresa May to say he was "wrong" to have done so.

At the time, the president lashed back at Mrs May in a tweet addressed directly to her: "Don't focus on me, focus on the destructive Radical Islamic Terrorism that is taking place within the United Kingdom. We are doing just fine!"

And his subsequent decision to pull out of an expected visit to London to open the new US embassy building fuelled speculation of a diplomatic rift.

But Mr Trump dismissed this as a "false rumour" when he met Mrs May at the World Economic Forum in the Swiss ski resort of Davos yesterday.

In his interview with Mr Morgan shortly afterwards, he insisted he had "a very good relationship" with the prime minister and would "love" to come to the UK.

Pressed by Mr Morgan about the Britain First tweets during his first international TV interview since becoming president, Mr Trump said: "I knew nothing about them and I know nothing about them today other than I read a little bit.

"Perhaps it was a big story in Britain, perhaps it was a big story in the UK, but in the United States it wasn't a big story.

"If you are telling me they're horrible people, horrible racist people, I would certainly apologise if you'd like me to do that."

He said he had made the retweets because he was concerned about the threat posed by radical Islamic extremists.

"They had a couple of depictions of radical Islamic terror. It was done because I am a big believer in fighting radical Islamic terror. This was a depiction of radical Islamic terror," he said.