The Trump administration is considering housing up to 20,000 unaccompanied migrant children on military bases in coming months, according to lawmakers and a Defense Department memo obtained by The Washington Post.

In a notification to lawmakers, the Pentagon said officials at Health and Human Services asked whether beds could be provide for children at military installations “for occupancy as early as July through December 31, 2018.”

U.S. Sen. Charles E. Schumer, D-New York, addressed the issue on the Senate floor Thursday morning.

“The Department of Defense has been asked whether it can house 20,000 unaccompanied children between now and the end of the year,” he said. “How will that work? Is it even feasible?”

The plan would seemingly have similarities to 2014, when the Obama administration housed about 7,000 unaccompanied children on three military bases. The Pentagon, in its congressional notification to lawmakers, said it must determine if it “possesses these capabilities.” As required under the Economy Act, the memo said, the Defense Department would be reimbursed for all costs incurred.

The sites would be run by HHS employees or contractors working with them, the memo said. They would provide care to the children, “including supervision, meals, clothing, medical services, transportation or other daily needs,” and HHS representatives will be present at each location.

The memo was sent to lawmakers Wednesday after President Donald Trump reversed his administration’s unpopular policy to separate children from their parents as they arrived at the southern U.S. border.

The president’s executive order directed Defense Secretary Jim Mattis to “take all legally available measures” to provide Homeland Security Secretary Kirstjen Nielsen with “any existing facilities available for the housing and care of alien families,” and the construction of new facilities “if necessary and consistent with law.”

Lt. Col. Jamie Davis acknowledged Thursday that the Pentagon received the request, and said the department is reviewing it.

The Trump administration spent months planning, testing and defending its family separation system at the border, taking more than 2,500 children from their parents in the six weeks prior to the president’s executive order Wednesday bringing it to a halt.

The U.S. government has been examining for weeks whether it can use military bases to house migrant children. Representatives from HHS visited three bases in Texas – Fort Bliss, Dyess Air Force Base and Goodfellow Air Force Base – last week to review their facilities for suitability, and were scheduled to review Little Rock Air Force Base in Arkansas on Wednesday, Davis said.

The Obama administration temporarily set up temporary centers in 2014 at three U.S. military bases: Fort Sill in Oklahoma, Lackland Air Force Base in Texas and Naval Base Ventura in California.

Asked about the possibility of military bases being involved again, Mattis said Wednesday that the Defense Department would “see what they come up with” in HHS, and that the Pentagon will “respond if requested.”

Mattis dismissed concerns about housing migrants on military bases now, noting that the Defense Department has done it on several occasions and for several reasons.

“We have housed refugees,” he said. “We have housed people thrown out of their homes by earthquakes and hurricanes. We do whatever is in the best interest of the country.”

The secretary, pressed on the sensitivities of the Trump administration separating children from their parents, said reporters would need to ask “the people responsible for it.”

“I’m not going to chime in from the outside,” he said. “There’s people responsible for it. Secretary Nielsen, obviously, maintains close collaboration with us. You saw that when we deployed certain National Guard units there, so she’s in charge.”

U.S. Sen. Jack Reed, D-Rhode Island, and U.S. Rep. Adam Smith, D-California, the leading members of the armed services committees, wrote a letter to Mattis on Wednesday requesting assurances that members of Congress would have access to any migrant facility established on a military base. The letter, sent before Trump dropped his family-separation policy at the border, said that it was essential to have access even in cases where only short notice is provided.

Mattis has approved temporarily detailing 21 military attorneys to the Justice Department to help with the glut of immigration cases that have emerged on the border. The order, issued earlier this month, calls for 21 attorneys with criminal-trial experience to assist as special assistant U.S. attorneys for 179 days, Davis said. They will help in prosecuting border immigration cases, he added, “with a focus on misdemeanor improper entry and felony illegal reentry cases.”

The possibility was raised in a congressional hearing in May, and first reported as underway by MSNBC on Wednesday night. U.S. law permits a judge advocate lawyer to be assigned or detailed to another agency, including to provide representation in civil and criminal cases.