Story highlights Donald Trump warned against letting Syrian refugees into the U.S.

The GOP front-runner warned of security risks

Washington (CNN) Donald Trump again warned of another 9/11-like attack on the United States if refugees are continually allowed into the country.

"Our country has enough difficulty right now without letting the Syrians pour in," the presumptive Republican nominee said in an interview on the National Border Patrol Council podcast Sunday morning, as first reported by BuzzFeed

On The Green Line podcast Trump also suggested ISIS is paying for refugees' cell phone plans.

"They all have cell phones so they don't have money, they don't have anything, they have cell phones," Trump said. "Who pays their monthly charges, right? They have cell phones with the flags, the ISIS flags on them."

Trump has repeatedly brought up the cell phones of Syrian refugees throughout his primary campaign, though its unclear what evidence he's referencing regarding their content.

Read More