Republican presidential front-runner Donald Trump has defended his call for a ban on Muslims entering the United States after it was used in a propaganda video by Somali militant group al-Shabab.

Donald Trump said people had praised his courage in truthfully highlighting a “problem” that others preferred to ignore.

During an appearance on CBS News, Donald Trump said: “Now people are getting involved.”

The tycoon’s call, after San Bernardino shooting in which 14 people died, has been widely condemned.

Democratic presidential candidate and former Secretary of State Hillary Clinton said that Donald Trump’s rhetoric was turning him into the “best recruiter” for ISIS.

A propaganda video by Al-Shabab, al-Qaeda’s Somali affiliate, used a clip of Donald Trump repeating his call at a campaign rally last month.

His appearance on CBS News’ Face the Nation, to be shown on January 3, Donald Trump was questioned over how his comments had been framed by al-Shabab as an incentive for Muslims to join holy war.

“Look, there’s a problem,” Donald Trump said.

“I bring it up. Other people have called and say you have guts to bring it up because frankly it’s true and nobody wants to get involved.

“People that are on different persuasions than me right now are saying, you know, maybe Trump isn’t wrong. We want to examine it.”

The video, released by al-Shabab’s media wing, also urges African-Americans to convert to Islam and take part in holy war. It says racism, police brutality and anti-Muslim sentiment are rife in the US.

In recent years, several Somali-Americans from Minnesota have gone to fight for al-Shabab in Somalia.

Al-Shabab, which seeks to overthrow Somalia’s Western-backed government and impose a strict version of Sharia, has carried out attacks in Kenya and Ethiopia.

Last month’s campaign statement from Donald Trump called for a “total and complete shutdown of Muslims” entering the United States until the authorities could “figure out what is going on”.