President Barack Obama says that Donald Trump is "exploiting" the anxieties of Americans who have been under economic stress in the wake of the recession, particularly "blue-collar men."

In an interview with NPR, Obama suggested that the combination of a changing economy and shifting demographics in the country have prompted uncertainty and fear in some parts of the population.

The president said that "particularly blue-collar men have had a lot of trouble in this new economy, where they are no longer getting the same bargain that they got when they were going to a factory and able to support their families on a single paycheck."

"You combine those things and it means that there is going to be potential anger, frustration, fear. Some of it is justified but just misdirected," he added. "I think somebody like Mr. Trump is taking advantage of that. That's what he's exploiting during the course of his campaign."

Obama made the comments during a year-end interview with NPR.

Trump, who remains the GOP frontrunner heading into the holiday season, has continued to draw fire from political foes.

After Hillary Clinton said in Saturday night's debate that his rhetoric about Muslims have made him "ISIS' best recruiter," Trump shot back that he's demanding an apology for the comment.

"She should apologize. She lies about emails. She lies about Whitewater. She lies about everything," he said on NBC's TODAY Show. "She will be a disaster as president of the United States."

Trump has also prompted outrage from both sides of the aisle for his praise of Russian president Vladimir Putin. He said over the weekend that he is "honored" by Putin's flattering statements about him, and he contended that he has not seen evidence of Putin's murder of journalists who cover his regime critically.