"You look at Israel and you look at others and they do it and they do it successfully," he said.
"I hate the concept of profiling, but we have to start using common sense," he told CBS News' Face the Nation. Trump also alleged that French authorities are monitoring mosques across their country, and said the US should "respectfully" do the same.
Loretta Lynch, the US attorney general, declined to directly respond to Trump's remarks. But following him as a guest on the show, she noted: "We look into everything– we look into everyone's community." Coordination with those communities, Muslim or any other, is a critical component to all federal terror investigations, she added.