Fox News host Chris Wallace challenged White House press secretary Sarah Huckabee Sanders on some of President Trump's claims about border security.

In an interview with Sanders on Sunday, Wallace took on the claim, made by Homeland Security Secretary Kirstjen Nielsen, that thousands of "special interest aliens" have been stopped at the border.

"But special interest aliens are just people who have come from countries that have ever produced a terrorist, they're not terrorists themselves," Wallace said. He also cited a State Department report saying that there has been no "credible evidence" of terrorists crossing the southern border from Mexico.

Sanders stood by the claim, saying that the southern border is the "most vulnerable point of entry."

"We know that, roughly, nearly 4,000 known or suspected terrorists come into our country illegally, and we know that our most vulnerable point of entry is at our southern border," she said, before Wallace cut her off.

"Do you know where those 4,000 people come, where they are captured?" Wallace responded. "Airports ... the state department says there hasn't been any terrorists found coming across the southern border."

Sanders then suggested that an "influx" of "terrorists" would flow through the border without increased security, such as Trump's proposed border wall.

"I'm not disagreeing with you that they're coming through airports," she said. "I'm saying that they come by air, by land and by sea, and the more and more that our border becomes vulnerable and the less and less that we spend time and money protecting it, the more that we're going to have an influx, not just of terrorists, but of human traffickers and drug inflow."

The exchange comes as the partial government shutdown, which began over Trump's demand for $5 billion in funding for a wall, enters its third week.

Sanders also told Wallace that Trump "means what he says" in suggesting that the shutdown could last for months or years.