The Pentagon says the acting defense secretary, Patrick Shanahan, has approved a plan to send about 320 more troops to the U.S.-Mexican border to provide additional support, such as driving Customs and Border Protection vehicles to transport migrants.

The decision announced Monday evening provides approval for a plan the Pentagon disclosed last Friday.

The Pentagon says the extra troop support will cost about $7.4 million through Sept. 30.

The decision allows the newly deployed troops to have contact with migrants when necessary to perform their tasks. In such cases, there are to be civilian Department of Homeland Security personnel nearby to conduct law enforcement functions.