Allowing some of the new 300 troops headed to the border to hand out meals to detained migrants has led the Pentagon to come up with an exception to a previous Defense Department policy to allow "incidental contact" with migrants.
Pentagon officials stressed that U.S. troops will continue to not engage in law enforcement duties.
Acting Defense Secretary Patrick Shanahan has still not signed the order authorizing the deployment that is part of the Department of Homeland Security's latest request for assistance from the Pentagon that was received on Thursday.
The new troops will join the 2,900 active duty troops and 2,000 National Guardsmen currently deployed to the border proving logistical support to DHS.
Because of their job functions, the new deployment will place U.S. troops in regular contact with migrants being detained by CBP personnel.
"We have border patrol stations where the CBP is literally overwhelmed with migrants," said Charlie Summers the acting Pentagon spokesman told reporters Friday. "We’re simply delineating the fact that we will have some of our troops handing out meals and therefore will come in contact with migrants."
"Our policy is the same as it was in 2006 when we had thousands of National Guard troops on the border monitoring and reporting to CBP," said Summers.
Though he acknowledged that an exception to that policy had been made to specifically allow 100 troops to come into incidental contact with migrants as they provide them with meals.
"There is no change, there is no waiver, it’s just us handing meals to migrants. Nothing else," said Summers.
According to Summers 160 new troops will provide transportation duties along the border, 100 general support troops will prepare and hand out meals to detainees and 20 military lawyers will help Immigration and Customs Enforcement in legal matters.
CBP law enforcement personnel will provide the security on all of the transport vehicles and the military drivers will drive from "within a segregated driver's compartment."
The new request from the Department of Homeland Security has been anticipated for weeks as the number of migrants along the border has swelled in recent months.
Acting Defense Secretary Patrick Shanahan told Pentagon reporters two weeks ago that he expected an increase in U.S. military support for the border.
"Our support is very elastic and given the deterioration there at the border you would expect that we would provide more support," Shanahan said.
According to CBP figures, the 92,000 migrants detained crossing the border in March was the highest monthly figure since 2007. Some 58,000 of those migrants were part of families crossing together, reflecting the new pattern of migrants attempting to cross the border.