The Pentagon has signed off on $1 billion for the U.S Army Corps of Engineers to support the Homeland Security Department and Customs and Border Protection in constructing a wall along the U.S.-Mexico border, the Department of Defense announced Monday.

Acting Defense Secretary Pat Shanahan approved the funds to go toward erecting 57 miles of 18-feet-high pedestrian fencing, and constructing and improving roads. The funds will also but used for installing lighting within the Yuma and El Paso sectors of the border.