FIRST ON FOX: 20 House Republicans on Friday wrote to the Department of Homeland Security requesting information on the number of Russians entering the U.S. via the southern border.

The Republicans, led by House Border Security Caucus co-chair Andy Biggs, R-Ariz., wrote to Homeland Security Alejandro Mayorkas informing him that "we have been made aware of an increase in illegal aliens from Russia illegally entering the United States."

BORDER PATROL TOLD TO CONSIDER EXEMPTING UKRAINIANS AT SOUTHERN BORDER FROM TITLE 42 RESTICTIONS: REPORT 

June 10, 2021: A pair of migrant families from Brazil pass through a gap in the border wall to reach the United States after crossing from Mexico to Yuma, Ariz., to seek asylum.   

June 10, 2021: A pair of migrant families from Brazil pass through a gap in the border wall to reach the United States after crossing from Mexico to Yuma, Ariz., to seek asylum.    ((AP Photo/Eugene Garcia, File))

"Given the Biden administration’s catch and release policies, we have serious concerns that Russians illegally entering the United States will simply be released into the interior with minimal vetting," they say in the letter.

"Releasing illegal aliens into our communities is a significant national security threat," they add.

The Russian invasion of Ukraine has sparked a refugee crisis, mainly from Ukraine, where millions have fled the violence into Europe, and has increased tensions dramatically between Washington and Moscow. Some of those displaced by the crisis have made the journey to the U.S., where many have relatives -- and have sought to enter via the southern border.

In February, 769 Russian migrants were encountered at the border in February, up from 72 in February 2021, according to Customs and Border Protection (CBP) data. That number has gone down since December, however, when 2,105 were encountered then -- significantly higher than the 53 encountered in Dec. 2021. The numbers for March, when Russia invaded Ukraine, are yet to be released by CBP

The Wall Street Journal reported that some 30,111 Russians entered Mexico in January and February, compared with an average of 12,380 in each of the past five years. The Journal reported that most entering the U.S. are handing themselves in at ports of entry rather than attempting to evade Border Patrol agents. Multiple reports have detailed how at least some of those fleeing Russia are anti-Putin dissidents.

ICE has suspended deportation flights to Russia, Ukraine and other countries in the region amid the ongoing instability.

BIDEN ADMINISTRATION GIVES PROTECTION FROM DEPORTATION TO UKRAINIANS LIVING IN US 

DHS recently extended temporary protected status (TPS) to Ukrainians, and has also issued a memo telling Border Patrol to consider Ukrainians for exemptions to TItle 42 expulsions -- but has not made similar moves for Russian nationals.

In the letter, the Republicans ask if there have been any additional vetting procedures for Russian nationals, how many have been encountered and how many have been detained – as well as the number of those released or paroled into the United States, and the number of those deported from the U.S.

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It marks the latest instance of Republican-led oversight of the crisis at the southern border, where Republicans have been pinning the blame for an ever-deteriorating migrant crisis on the policies of the Biden administration. The administration says it is preparing for an increase in migrants in the coming months, just as it is considering ending Title 42 public health protections.