"Currently we have approximately 3,150 supporting customs and border patrol along the southwest border with approximately 1,050 in… Texas corridor, 900 in Arizona, and 1,200 in California," Manning said. "The department will continue to assess requirements to meet CBP needs."
On November 30, Defense Secretary James Mattis approved the Department of Homeland Security's request to extend the deployment of troops currently stationed along the US-Mexico border through the end of January. The original request was set to expire on December 15.
The active duty military personnel were deployed to the US southwest border in October to assist the Customs and Border Protection (CBP) upon the arrival of migrant caravans from Central America.