Donald Trump doubled down on his controversial statements calling for restrictions on Muslims entering the United States during an extended interview with CNN’s Anderson Cooper on Thursday.

When asked whether he felt Islam was “at war with the West,” the GOP frontrunner told Cooper “I think Islam hates us.”

“There is something there,” Trump continued, “that is a tremendous hatred there. There’s a tremendous hatred. We have to get to the bottom of it. There’s an unbelievable hatred of us.”

Trump once again raised the issue of Muslims entering the United States, calling for vigilance, arguing that distinguishing between radicals and moderates can be difficult.

“There is a tremendous hatred. We have to be very vigilant, we have to be very careful, and we can’t allow people coming into this country who have this hatred of the United States and of people that are not Muslim.”

“It’s very hard to define, it’s very hard to separate because you don’t know who’s who.”

Florida Senator Marco Rubio bashed Trump for his comments, noting that while he agreed “there is problem with radical Islam,” an American president must not paint all Muslims with the same brush.

“How does the President of the United States who goes around saying these things now reach out to the king in Jordan or the president in Egypt…if you’re going around and saying ‘all of you hate America’?”

When asked to clarify his comments during Thursday’s GOP debate, Trump stood by his earlier comments. In response to a moderator’s question on whether Trump’s comments included all 1.6 billion Muslims worldwide, Trump responded, “I mean a lot of ‘em, I mean a lot of ‘em.”

“I’ve been watching the debate today and they’re talking about radical Islamic terrorism or radical Islam, but I will tell you there’s something going on that maybe you don’t know about and maybe a lot of other people don’t know about, but there is a tremendous hatred and I will stick with exactly what I said to Anderson Cooper.”

Republican voters appear to back Trump’s rhetoric. A Pew poll in January shows that 65% of Republicans want a president who will “speak bluntly” about Islam, versus only 29% who said they wanted a president who would be “careful not to criticize Islam as a whole.”