Responsibility for unaccompanied children and families who arrive in the U.S. via the southern border appeared to shift to the U.S. military on Thursday, as the Trump administration called on the Pentagon to make preparations to house approximately 20,000 children on military bases.

Following President Donald Trump's executive order in which he directed federal agencies to prepare detention facilities to house families together and to end the forcible separation of families, Pentagon officials agreed to determine whether military bases in Arkansas and Texas could house families and unaccompanied minors.

According to the Washington Post, the arrangement would involve housing children on military bases for at least six months, until the end of 2018.

The deal between the Pentagon and the Department of Health and Human Services (HHS), which oversees the care and supervision of unaccompanied children who immigrate to the U.S. via the southern border, follows reports that Defense Secretary James Mattis would send more than 20 military attorneys to border states to assist in prosecuting immigrants.

The Trump administration originally examined the possibility of housing children on military bases in May, shortly after Attorney General Jeff Sessions introduced his "zero tolerance" policy under which more than 2,000 children have been separated from their parents, and before the practice drew international condemnation and widespread protests which ultimately forced Trump to sign his executive order.

The original reports drew comparisons to World War II-era internment camps from critics.