Image copyright AP Image caption Ms Clinton will not be apologising for comments that Donald Trump helps IS recruit

Hillary Clinton has defended her claim that the so-called Islamic State is using videos of Donald Trump's anti- Muslim rhetoric to attract followers.

Mr Trump disputed that the videos exist and demanded an apology, to which Ms Clinton's spokesman said "hell no".

During Saturday's debate, Ms Clinton said the Republican front-runner was becoming the group's "best recruiter".

Mr Trump has called for a ban on Muslims entering the US, drawing criticism from around the world.

Despite providing no evidence, Mr Trump has also said US Muslims in New Jersey cheered the 9/11 attacks. He has also opposed the resettlement of Syrian refugees in the US.

Rivals in both parties have accused Mr Trump of xenophobia and preying on Americans' heighten fears about terrorism after attacks in Paris and San Bernardino.

Media playback is unsupported on your device Media caption Laura Bicker reports from New Hampshire: Hillary Clinton said Donald Trump was ''Isis's best recruiter''

Earlier, a spokeswoman for Ms Clinton's campaign said they are not aware of a specific Islamic State video featuring Mr Trump, but that jihadis use Mr Trump's comments about Muslims for recruitment.

"She lies about everything," Mr Trump said, adding that the Democratic front-runner was "making up tapes and video which don't exist".

"Hell no. Hillary Clinton will not be apologizing to Donald Trump for correctly pointing out how his hateful rhetoric only helps [Islamic State] recruit more terrorists," spokesman for Ms Clinton Brian Fallon told CNN.

Meanwhile, President Barack Obama told NPR that Mr Trump is "exploiting" the anger and fear among blue-collar men in the current US economy.

Image copyright Reuters

Economic and demographic changes in the country allows for Mr Trump to spread ideas, he said.

Of that fear and anxiety, "some of it [is] justified, but just misdirected," Mr Obama said.

"I think somebody like Mr. Trump is taking advantage of that. That's what he's exploiting during the course of his campaign."

NBC asked Mr Trump if he was holding Ms Clinton to a double standard because he could not back up his own claim that people in New Jersey were cheering when the World Trade Center collapsed on 9/11.

He said he had been "totally exonerated" from that and that he had been proven right.