The Biden administration announced Tuesday that it is expanding the entry of migrants into the U.S. who had been kept in Mexico as part of the Trump-era Migrant Protection Protocol (MPP) – even as migrants continue to surge toward the border in record numbers.

The Biden administration ended the program, known as the "Remain-in-Mexico" policy, and began what it described as a "phased" entry of migrants who had been kept south of the border in February. Officials said approximately 25,000 migrants were waiting in Mexico as part of MPP.

US BEGINS ADMITTING MIGRANTS FROM MEXICO, AS BIDEN ADMINISTRATION WINDS DOWN TRUMP-ERA POLICY 

It unravels one of the core policies put in place by the Trump administration to deal with the 2019 crisis. The expansion of MPP, with Mexican cooperation, saw migrants held south of the border while their cases were heard at nearby court tents.

Proponents said it ended the pull factor by not allowing migrants to be allowed into the U.S. just by making an initial asylum claim, but critics said it was cruel and kept migrants in danger. 

After scrapping the program, the administration set up a virtual registration system, where migrants are given a date and time to appear at a staging site in Mexico, before being transported to a point of entry.

On Tuesday, the Department of Homeland Security said processing would expand to the port of entry in Eagle Pass, Texas, where those who had been registered and tested for COVID-19 would be processed.

"This system to process individuals with active MPP cases is the first phrase of a program to restore safe and orderly processing at the Southwest border," a DHS spokesman said. "Physical presence at a port of entry is not the way to gain access to this phased effort. The United States is continuing to strictly enforce existing immigration laws, as well as COVID-19-related travel and border restrictions."

TEXAS, MISSOURI SUE BIDEN ADMINISTRATION OVER SCRAPPING OF 'REMAIN-IN-MEXICO' POLICY 

The Biden administration has been facing sustained criticism for its handling of the crisis at the southern border, which has seen 172,000 migrant encounters in March alone, with increased numbers of unaccompanied children in custody and migrant families being released into the U.S. without court dates.

Republicans have blamed the Biden administration for rolling back border protections like MPP, saying it has encouraged migrants to make the trek north. The administration has denied there is a crisis, and has blamed the prior administration for dismantling pathways to asylum.

"The border remains closed," the DHS spokesperson said on Tuesday. "No one should believe smugglers or others claiming otherwise."

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The announcement comes hours after Texas and Missouri sued the administration to reinstate the program, saying it was harming both states at the border and further into the interior.

"President Biden could immediately remedy the influx of crime pouring across our border by reinstating the Migrant Protection Protocols," Texas Attorney General Ken Paxton said in a statement. "Dangerous criminals are taking advantage of the lapse in law enforcement and it’s resulting in human trafficking, smuggling, a plethora of violent crimes, and a massive, unprecedented burden on state and federal programs for which taxpayers must foot the bill."