Republican presidential candidate and former Florida Gov. Jeb Bush said in a radio interview Tuesday that "you can tell when someone is a Christian in the Middle East" based on indicators such as their name and birth certificate.

"I can promise you that," Bush told New Hampshire radio host Jack Heath. "By name, by where they're born, their birth certificates. There are ample means by which to know this."

In the interview, Bush reiterated his call for pressing "the pause button" on accepting Syrian refugees to ensure that refugee screening processes are "proper."

Bush said last week that he would ultimately be willing to admit some refugees, such as orphans or Christians, to the U.S. When asked how to prove that someone is Christian, he said then, "You're a Christian — I mean, you can prove you're a Christian. You can't prove it, then, you know, you err on the side of caution."

On Tuesday, Bush also repeated that he feels the country has a "moral obligation" to support Syrian Christians.

"I've used the example of Syrian Christians that are — but for the United States and but for the world community, they'll be slaughtered, beheaded, raped, pillaged, because of their faith," Bush said. "I think we have a moral obligation to support them."