The new military zone is located in Cameron and Hidalgo Counties in Texas and will be transferred from land overseen by the International Boundary and Water Commission, an entity that settles treaty issues between the U.

The Defense Department is expanding its border role with a new military zone near Yuma, aiming to boost surveillance as crossings continue to fall.

The move brings to four the number of "National Defense Areas" near the border where U.S. military personnel can temporarily detain undocumented migrants for trespassing.