Reince Priebus, the incoming White House chief of staff, spoke out about the "problematic" aspects of Islam. His comments Sunday came while defending former Lt. Gen. Michael Flynn's controversial comments about Muslims.

Asked on ABC whether future National Security Adviser Flynn advocates President-elect Donald Trump's view of Islam, Priebus answered: "I think so." Flynn reportedly said Islam is a political ideology that hides behind being a religion.

"Look I'm not going to rule out anything," Priebus reportedly said. "We're not going to have a registry based on a religion. But what I think what we're trying to do is say that there are some people, certainly not all people... there are some people that are radicalized. And there are some people that have to be prevented from coming into this country." 

He added, "And Donald Trump's position, President Trump's position is consistent with bills in the House and the Senate that say the following: If you want to come from a place or an area around the world that harbors and trains terrorists, we have to temporarily suspend that operation until a better vetting system is put in place."

"Clearly there are some aspects of that faith that are problematic and we know them; we've seen it," Priebus reportedly said. "It certainly isn't a blanket for all people of that faith, but Mike Flynn is one of the most highly respected intelligence officers in America. Certainly no one can deny that."

However, Priebus did not explicitly define the aspects of Islam he thought "problematic."

Last week, Flynn said he agreed with Trump's initial proposal to temporarily ban Muslims from entering the U.S. He also accompanied Trump to his first top-secret national security briefing in August this year.

“I am pleased that Lieutenant General Michael Flynn will be by my side as we work to defeat radical Islamic terrorism, navigate geopolitical challenges and keep Americans safe at home and abroad,” Trump said in a statement last week. “General Flynn is one of the country’s foremost experts on military and intelligence matters and he will be an invaluable asset to me and my administration.”