White House press secretary Sarah Sanders on Sunday repeated a false claim put forth by her and other Trump administration officials about the number of suspected terrorists apprehended at the southern border, one that is contradicted by the administration's own data on the topic.

Sanders appeared on "Fox News Sunday" with Chris Wallace and was asked about comments made by Homeland Security Secretary Kirstjen Nielsen last week. Nielsen said Customs and Border Protection "has stopped over 3,000 what we call 'special-interest aliens' trying to come into the country in the southern border. Those are aliens who the intel community has identified are of concern."

Wallace pointed out that special-interest aliens are those hailing from "countries that have ever produced a terrorist. They're not terrorists themselves." Wallace cited a State Department report stating there is "no credible evidence" of terrorists crossing the border with Mexico.

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Sanders responded by connecting the issue of terrorism with the fight over border security.

"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," Sanders said. In an appearance on "Fox and Friends" on Friday, Sanders falsely said last year there were "nearly 4,000 known or suspected terrorists that CPB picked up that came across our southern border."

Wallace interjected on Sunday, saying he had "studied up" on the statistic.

"Do you know where those 4,000 people come [from], where they're captured? Airports," Wallace said.

"I'm saying that they come by air, by land and by sea," Sanders replied. "I'm not disagreeing with you that they're coming through airports."

Here's the video of Chris Wallace fact-checking Sarah Sanders on her false claim that terrorists are streaming over the border with Mexico. "The state department says there hasn’t been any terrorists found coming across the southern border." Via Fox. pic.twitter.com/ByMaa9TK2S — Kyle Griffin (@kylegriffin1) January 6, 2019

According to statistics from the Department of Justice and the Department of Homeland Security, 2,554 people on the FBI's terrorist screening list were stopped trying to enter the U.S. in fiscal year 2017, the most recent year for which data is available. The majority — 2,170 — were attempting to enter through airports, and 49 were attempting to enter by sea.

The report found 335 were attempting to enter by land. The State Department said in September it had no indication that any terrorists had tried entering the U.S. through Mexico.

"At year's end there was no credible evidence indicating that international terrorist groups have established bases in Mexico, worked with Mexican drug cartels, or sent operatives via Mexico into the United States," the State Department report said. "Terrorist groups likely seek other means of trying to enter the United States."

The claim that the southern border is vulnerable to terrorists has been repeated by top Trump officials for months. Vice President Mike Pence told the Washington Post in October the U.S. apprehended more than 10 terrorists or suspected terrorists per day at the southern border in the last fiscal year.

And President Trump repeated the claim of a terrorist threat in a Rose Garden press conference Friday.

"The border is a much more dangerous problem. It's a problem of national security. It's a problem of terrorists," Mr. Trump said. "They find it's the easiest place to come through. They drive right in and make a left. It's not going to happen."