WASHINGTON — The U.S. Department of Homeland Security has formally requested space for up to 12,000 beds at a military base to detain families caught crossing the border illegally, two Trump administration officials said Wednesday.

The request asks for 2,000 beds to be up and running in the next 45 days, and the remaining space to be available on an as-needed basis.

[Related: DOD to house 20,000 immigrant children on military bases as early as July]

The request notes the space is for both male and female heads of households. The facility must comply with U.S. Immigration and Customs Enforcement's family residential standards, as well as a 1997 agreement known as the Flores settlement, which governs how children are housed in immigration custody.

Story continues below

Those standards require air conditioning, libraries, private showers, plus medical, dental, and mental health facilities. Those rules also state that housing requires freedom of movement within the facility.

The facility will be housed at a military base, but it's not clear yet which one. Defense Secretary Jim Mattis said Monday that two bases had been identified to house migrants: Goodfellow Air Force Base near San Angelo, Texas, and Fort Bliss in El Paso, Texas, which comprises more than 1 million acres in Texas and New Mexico.

The funding is being worked out; it will be staffed by Homeland Security officials and there will be no impact to training or military readiness, the officials said. The officials were not authorized to release details of the request publicly and spoke to The Associated Press on condition of anonymity.

Right now, three family detention centers — with a total of about 2,500 beds —are operating essentially at capacity.

Children generally can only be detained with their families for up to 20 days under the Flores agreement. Justice Department officials have requested the agreement be modified to allow for longer detention — a move that immigrant advocates say creates a second problem and doesn't solve the first issue.

More than 2,300 children were separated from their families under the zero tolerance policy. At least 500 have been reunited so far. President Trump last week issued an order that required families to remain together when caught at the border. A federal judge Tuesday night ruled that the administration has 30 days to reunify the remaining families and 14 days if the child is younger than 5.