More than 40 migrants on the terror watchlist have been arrested by Customs and Border Protection (CBP) trying to enter the country illegally since President Biden took office, according to newly released CBP data.

The data, sent to lawmakers in response to a congressional inquiry and obtained by Fox News Digital, says that since Jan. 20, 2021, U.S. Border Patrol and the Office of Field Operations has "arrested 42 subjects who were on the terror watchlist and attempted to enter the United States illegally." 

BORDER PATROL STOPPED 23 PEOPLE ON TERRORIST DATABASE AT SOUTHERN BORDER IN 2021: CBP DATA 

The Terrorist Screening Database (TSDB) contains information about the identities of those who are known or "reasonably suspected" of being involved in terrorist activities. Republican lawmakers have repeatedly called for the number of those encountered at the border to be made public by the administration.

The number does not count the number who got past overwhelmed Border Patrol agents at the southern border. Fox News reported earlier this month that over 62,000 illegal immigrants evaded Border Patrol agents in March alone, averaging about 2,000 a day. 

U.S. Border

Border Patrol vehicles are stationed at a popular crossing point for migrants from Central America on April 29, 2021 near Yuma, Arizona. (Photo by Andrew Lichtenstein/Corbis via Getty Images)

The latest information from CBP comes in response to an inquiry in August from 20 House Republicans led by Rep. Chip Roy, R-Texas, which called for the Department of Homeland Security to provide a slew of information about the ongoing crisis at the southern border.  The lawmakers asked for the number of migrants who entered unlawfully and "are included on a list maintained by the Federal Government relating to terrorists or individuals prohibited from boarding a commercial aircraft."

The lawmakers had hit out at the agency for a lack of transparency.

HOUSE REPUBLICANS PUSH BIDEN ADMIN FOR INFORMATION ON MIGRANTS ON TERROR DATABASE

"Due to the unprecedented nature of this crisis, it is dangerously irresponsible for your Department to not be as transparent as possible with the American people, the states of this union and the localities facing the frontline effects of this crisis," that letter said.

Fox News had previously reported that 23 individuals had been apprehended across the southern border by Border Patrol between Jan. 20 and the end of December. This latest figure includes the Office of Field Operations (OFO) data, and therefore includes those encountered at ports of entry. The information includes nationwide arrests and is not specific to the southern border.

Former Border Patrol Chief Rodney Scott had repeatedly sounded the alarm over the number of TSDBs coming across the border, telling fellow agents last year that it was "at a level we have never seen before."

WHITE HOUSE SAYS TERRORIST ENCOUNTERS AT BORDER ‘UNCOMMON,' TOUTS BORDER PATROL FOR ‘DOING THEIR JOB’ 

"We have terrorist threats we can’t get into in this type of a forum but they are real," he told Fox News’ Bret Baier in October.

The number of TSDB encounters comes as the Biden administration released its border numbers for March on Monday, showing more than 220,000 encounters -- the highest of Biden’s presidency. 

The data sent by CBP to lawmakers also details the costs of the care of migrants. Since January 20, CBP has spent $95 million of federal funding on personnel, $338 million on infrastructure, $98 million on utilities and food and $166 million on healthcare. Additionally, it has spent $12 million on transporting migrants by vehicle and $36 million on transporting them by airplane.

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Both Republicans and Democrats have expressed concerns over the Biden administration’s plan to lift the Title 42 public health order at the end of May, which has been used to expel a majority of migrants at the border -- with lawmakers fearing it will lead to an even bigger surge in migration to the already overwhelmed border.