Chris Wallace fact checks Sarah Huckabee Sanders' border security narrative. He used a report from Trump's State Dept. to do it.

During an appearance on "Fox News Sunday," White House press secretary Sarah Huckabee Sanders pushed debunked claims about terrorists in order to promote the Trump administration's narrative about the border.

But Fox News anchor Chris Wallace had done his homework — and was having none of it.

What happened?

Clarifying whether President Donald Trump is firm in his commitment to allow the government shutdown to go on for "years" in order to receive funding for his border wall, Wallace noted that Trump's decision drastically impacts millions of Americans, aside from the approximately 800,000 furloughed government employees.

Sanders confirmed Trump's commitment.

Wallace then shifted the conversation to the border wall. The Trump administration says, among other reasons, that a border wall would prevent terrorists from entering the U.S. On Friday, Homeland Security Secretary Kirstjen Nielsen said the U.S. has detained 3,000 "special interest aliens" who crossed the border. She attempted to imply those detained were suspected terrorists.

However, Wallace noted that, according to a September State Department report, "'special interest aliens' are just people who have come from countries that have ever produced a terrorist, they're not terrorists themselves. The State Department says, 'There were no credible evidence of any terrorist coming across the border from Mexico.'"

"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 southern border," Sanders tried to explain.

But Wallace knew the facts.

"I know the statistic, I didn't know if you were going to use it, but I studied up on this," Wallace said. "Do you know what those 4,000 people come where they are captured? Airports!"

"Not always," Sanders attempted to say.

"The State Department says there hasn't been any terrorists found coming across the southern border from Mexico," Wallace explained again.

"It's by air, it's by land, it's by sea, it's all of the above," Sanders replied. "But one thing that you're forgetting is at the most vulnerable point of entry that we have into this country is our southern border and we have to protect it. And the more and more individuals that know—"

"But they're not coming across the southern border, Sarah, they're coming and they're being stopped at airports," Wallace interjected.

Sanders continued to restate her talking points, claiming the southern border is the most vulnerable entry point in the U.S. that needs immediate attention in order to bolster protection and ensure Americans' safety.