US presidential contender Donald Trump says many Muslims are “phenomenal” people, but some of them pose a “problem” for the United States.

The front-runner Republican candidate made the remarks in an interview with CNN on Wednesday when asked to comment on a September incident at a rally in New Hampshire where a Trump supporter ranted against Muslims and asked him how he planned to eradicate "terrorist training camps."

Trump just sought to laugh off the comment at the time. He was criticized by many rival candidates for not forcefully denouncing the man and failing to correct him when he called President Barack Obama a Muslim and non-American.

Trump told CNN's Don Lemon that he would not handle the situation differently if it were to arise again.

“He said Muslims are a problem, OK? That's what he said, OK? Are they a problem? You tell me,” the New York billionaire said.

“I don't see the people ... that knocked down the World Trade Center going back to Sweden. OK? So he said Muslims are a problem,” he added.

Asked whether he personally believes Muslims are posing a problem to the US, Trump responded, “I think a certain segment are certainly a problem.”

“Unless you want to be so politically correct where you want me to say, 'Oh, absolutely not,’” he added.

Russia ‘fighting ISIL’ in Syria

Elsewhere in his remarks, the real estate tycoon said he supports the Russian campaign to destroy the Daesh (ISIL) terrorist network in Syria.

Tump said he believes Russia has started airstrikes against the terrorists because Moscow wants to wipe them out.

"If Russia wants to go in and if Russia wants to fight — in particular ISIS, and they do and one of the reasons they do is because they don't want ISIS coming into their country and that's going to be the next step. So that's why they're there," he said. "I think they will be fighting ISIS."

Trump also advised the United States not to interfere with the Russian mission against Daesh in Syria.

On Wednesday morning, Russia carried out its first airstrikes against Daesh terrorists near the Syrian city of Homs.

Russia started the air campaign after the upper house of its parliament gave President Vladimir Putin approval to use force in Syria.

Syrian President Bashar al-Assad has welcomed Russia’s decision to bomb ISIL terrorists, saying Moscow is providing military support on a request from Damascus.