The Pentagon has been asked to supply up to 20,000 beds at old military bases for migrant children held after illegally entering the US, officials have said.
Beds will be for migrant children who crossed the border unaccompanied, as well as those separated from parents, reports BBC.
The moves follow the US President Donald Trump's reversal of the controversial separation policy of separating children from their parents.
US First Lady Melania Trump visited a facility for migrant children in Texas saying she wanted to reunite families.
But her visit to the facility for young migrants was thrown into controversy after she was photographed wearing a jacket with the words "I really don't care do u?" as she boarded the plane to Texas.
At least 2,300 children have been taken from their parents since 5 May after entering the country without documentation at the US-Mexico border.
While the adults are held in custody pending court appearances, the children are being sent to holding cells, converted warehouses and desert tents under the "zero tolerance" policy introduced in April.
Officials have also gone to court to try to lengthen the time children can be held as parents are prosecuted.
A vote on a Republican bill on immigration has been postponed until at least Friday as it does not have enough support in the House of Representatives.
Mr Trump had said that only Congress could resolve the issue of separated families but on Wednesday he signed an executive order to keep children with their families but in detention.