U.S. Soldiers, assigned to 3rd Platoon, Bravo Company, 1st Battalion 12th Infantry Regiment, patrol the southern border outside of Sierra Blanca, Texas, on March 31, 2025. Under the direction of U.S. Northern Command, Joint Task Force – Southern Border aligns efforts to seal the border and repel illegal activity. PFC. MALIK WADDDY FIFFEE/U.S. ARMY
United States President Donald Trump, in a national security memo signed April 11, authorized the transfer of federal land along the U.S.-Mexico border to the U.S. Department of Defense (DOD) to support the mission to halt illegal immigration. The 60-foot-wide, 700-mile-long strip of land, known as the Roosevelt Reservation, runs along the international border from California through Arizona into New Mexico. It had been managed by the departments of the Interior and Homeland Security.
The federally owned portions of the Roosevelt Reservation will be designated as National Defense Areas and considered military installations, meaning those who walk on the land could be detained by U.S. Soldiers and face legal action by civilian law enforcement. The memo notes that “Federal Indian reservations” are excluded from the land transfer.
“Service members stationed at the border and operating on that land will have greater authority to execute their mission,” a DOD News article says. “They will be governed by the same rules as when they are defending any other military installation, such as apprehending trespassers and passing them to appropriate civilian or federal law enforcement officials.”
Before the release of the memo, titled “Military Mission for Sealing the Southern Border of the United States and Repelling Invasions,” Soldiers already had begun conducting border patrols. A U.S. Northern Command (USNORTHCOM) order in late March approved the patrols, which the command said would give troops more maneuverability to support their Customs and Border Protection partners. Their mission is to repel unlawful mass migration, narcotics trafficking, migrant smuggling, human trafficking and other cross-border criminal activities.
Service members at newly established National Defense Areas “will construct and position temporary barriers, detect and monitor the use of routes across or adjacent to the area and apprehend individuals who breach the barriers,” the DOD News article says. Signs and barriers will show where the boundaries are. For a 45-day period, the Defense Department is testing control of part of the Roosevelt Reservation in New Mexico, east of Fort Huachuca, an Army installation in Arizona, a U.S. official told The Associated Press.
Military border operations fall under USNORTHCOM’s jurisdiction. In testimony before the Senate Armed Services Committee on February 13, 2025, Gen. Gregory M. Guillot, commander of USNORTHCOM and the North American Aerospace Defense Command (NORAD), said: “Unprecedented flows of illicit drugs and migrant smuggling across the U.S. southern border have created a crisis that undermines national security and the safety of citizens and communities across the country. The dynamic operational environment and evolving threats to North America require USNORTHCOM and NORAD to execute new missions on a moment’s notice without sacrificing ongoing operations and future planning.”
The number of U.S. troops deployed or scheduled to deploy to the Mexico-U.S. border has surged to more than 10,000, USNORTHCOM said in a March 17 news release. In addition, a motorized brigade equipped with 20-ton armored Stryker combat vehicles and a helicopter battalion were ordered to the region. The news release said the number of personnel at the border will fluctuate as units rotate personnel and as more forces are deployed after plans are finalized.