Updated

The Biden administration has approved sending 1,500 active duty U.S. troops to the southern border in the coming days amid concerns that tens of thousands of migrants will surge into the country once Title 42 is lifted, sources tell Fox News. 

The U.S. soldiers will come from a variety of active duty Army units and will serve for 90 days in mostly administrative and transport roles to free up law enforcement and Border Patrol, according to two senior U.S. officials familiar with the deliberations. 

The 90-day deployment is not inconsistent with support to the border going back to the George W. Bush administration, National Security Council spokesman John Kirby said. The Pentagon said the Department of Homeland Security requested the troops, which will arrive as early as May 10.

Officials said the troop deployment would be similar to deployments to the border ordered by former President Donald Trump. The troops would be armed for self-defense but would not assist with law enforcement. 

"For 90 days, these 1,500 military personnel will fill critical capability gaps, such as ground-based detection and monitoring, data entry, and warehouse support, until CBP can address these needs through contracted support," Pentagon press secretary Brig. Gen. Pat Ryder said in a statement. "Military personnel will not directly participate in law enforcement activities. This deployment to the border is consistent with other forms of military support to DHS over many years."

Customs and Border Protection (CBP) has previously warned migrants that illegal entry into the U.S. "will result in removal." The Biden administration is encouraging migrants to use the CBP One app to schedule appointments at points of entry where their asylum claims can be processed. 

WITH TITLE 42'S END A MONTH AWAY, BIDEN ADMIN MAKING MOVES TO DEAL WITH SURGE

The U.S. southern border

View of cargo containers placed by the U.S. authorities as a retaining wall on the banks of the Rio Grande in Ciudad Juarez, Chihuahua state, Mexico, on Dec. 28, 2022. (Erika Martinez/AFP via Getty Images)

The reality of the government's response to the migrant crisis doesn't reflect the Biden administration's official position. While many are returned currently due to the Title 42 order – which allows for the rapid removal of migrants at the border due to the ongoing COVID-19 pandemic – not all who enter illegally have been returned via the order.

CBP statistics show that only about 46% of migrant encounters at the border resulted in a Title 42 expulsion. Meanwhile, Homeland Security Secretary Alejandro Mayorkas testified to Senate lawmakers last month that of the nearly 1.3 million migrants in FY 2022 who were processed via Title 8, only about 360,000 were deported.

The White House said Tuesday that troops to the border "would not be necessary if Congress would act."

"As you know, on the first day of walking into the White House of his administration, the president put forth a comprehensive immigration legislation and so that we could have resources and so that we could be able to help the men and women of Border Patrol to do their jobs," White House press secretary Karine Jean-Pierre said. "And so if Congress would act and again, do their jobs and meet us halfway and do this in a bipartisan way, we would not have to do this."

Those who aren't deported are placed into immigration removal proceedings and released into the U.S. pending their hearings – which can take years. Immigration and Customs Enforcement (ICE) data shows deportations have plummeted under President Biden.

OVER 99% OF MIGRANTS WHO HAVE SOUGHT TITLE 42 EXCEPTION VIA CBP ONE APP WERE APPROVED

Crowds at Mexican border

Migrants walk into U.S. custody after crossing the border from Mexico, March 29, 2023, a day after dozens of migrants died in a fire at a migrant detention center in Ciudad Juarez.  (AP Photo/Christian Chavez)

In preparation for the end of Title 42, the Biden administration has developed a new asylum rule that will bar migrants from being eligible to claim asylum if they have crossed into the U.S. illegally, have not scheduled an appointment via the CBP One app, and have not claimed asylum in a country through which they previously passed.

While Mayorkas has stressed that the "presumption of ineligibility" will be rebuttable and there are exemptions made for some people, it has enraged some Democrats and immigration activists who claim it is similar to the Trump-era transit ban and that it encroaches on the right of anyone from anywhere in the world to claim asylum at the U.S. border.

Sending troops to the border is likely to anger the left and draw more comparisons of Biden to Trump. 

BIDEN ADMIN WARNS MIGRANTS THAT ENTERING ILLEGALLY ‘WILL RESULT IN REMOVAL’ AMID FEARS OF POST-TITLE 42 SURGE

Migrants Venezuela border security

Border Patrol agents encounter over 1,000 migrants in El Paso, Texas, March 29, 2023. (Customs and Border Protection)

The expected migrant surge has prompted the administration to work more closely with Mexican authorities and NGO partners and look for alternative removal authorities under Title 8. 

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Last month, Fox News Digital reported that the administration is preparing to hold "credible fear" screenings – the first step in claiming asylum – for migrants in CBP facilities. The Department of Homeland Security confirmed the agency is working with legal service providers "to provide access to legal services for individuals who receive credible fear interviews in CBP custody."

Fox News' Adam Shaw contributed to this report.