The Department of Defense sent about 5,800 active duty, reserve, and National Guard forces, including 1,100 Camp Pendleton-based Marines, to the southern border ahead of the ongoing migrant caravan.
On Monday, U.S. Customs and Border Protection temporarily shut down all northbound lanes into the U.S. at the San Ysidro Port of Entry so troops could position moveable barriers, the agency said.
Homeland Security Secretary Kirstjen Nielsen called this part of the “hardening efforts,” claiming “a large # of caravan migrants were planning to rush the border in an attempt to gain illegal access to the US,” in a tweet.
San Ysidro is the border’s busiest crossing, with about 110,000 people entering the U.S. every day. That traffic includes some 40,000 vehicles, 34,000 pedestrians and 150 to 200 buses.
U.S. Marine Lt. Dustin Pavlick said his platoon of about 45 Marines was working on "construction and reinforcing this obstacle to support the mission of Customs and Border Protection."
Their goal was to get “a half a mile of wire on this wall,” Pavlick said.
The Department of Defense said the troops would not interact with migrants but would complete "border hardening" tasks, like using pieces of barbed wire, concrete roadblocks and rebar to create movable barriers that can be used to block lanes at the San Ysidro and Otay Mesa Ports of Entry.
Analysts and the Pentagon estimate that the entire deployment operation could cost $200 million.
Here's a look into the United States' "border hardening" efforts: