FORT BLISS, Texas –
Joint Task Force–Southern Border, a newly announced headquarters element from the 10th Mountain Division, assumed control of the southern border mission on March 14, 2025.
“This is an important step in the whole-of-government effort to secure the southern border and maintain U.S. sovereignty and territorial integrity,” said Gen. Gregory M. Guillot, commander of U.S. Northern Command. “Joint Task Force–Southern Border will lead as both the synchronizer of all joint capabilities and the land force commander for U.S. Northern Command as we conduct operations along the southern border, building upon the excellent foundation set by Joint Task Force–North.”
The transfer of authority from Joint Task Force–North to Joint Task Force–Southern Border aligns all efforts under a single joint task force, enabling more effective and efficient Department of Defense operations.
Mission
Following President Trump’s executive order “Protecting the American People Against Invasion,” the Department of Defense has made securing the southern border a top priority. The department also supports the Department of Homeland Security and U.S. Customs and Border Protection in ensuring 100% operational security.
The mission is to conduct all-domain operations to control the U.S. southern border in support of CBP, protecting the territorial integrity of the United States.
Joint Task Force–Southern Border was activated to provide command and control for forces not aligned under the Joint Task Force–North mission set. JTF–North will return to its core mission of countering transnational criminal organizations, while JTF–Southern Border executes U.S. Northern Command’s full-scale, agile, and simultaneous multi-domain operations.
All Title 10 service members previously assigned to JTF–North for border support have been realigned under JTF–Southern Border. Title 10 authority allows the president to activate National Guard and Reserve members for federal missions.
The organizational and manning changes impact how the Department of Defense supports DHS, but the scope of support remains unchanged. Specific tasks include detection and monitoring, warehousing and logistics, transportation, vehicle maintenance, training support, data entry, aviation operations, military engineering, and intelligence analysis. This assistance enhances DHS and CBP’s ability to carry out their law enforcement and immigration-related missions.
JTF–Southern Border brings together an organic Army unit with a legacy of successful global leadership and augmentees from all services to form an experienced, agile, and technologically advanced command, designed to leverage unique military capabilities in support of DHS.
Action
Joint Task Force–Southern Border oversees subordinate units across the 2,000-mile U.S.–Mexico border, from San Diego, California, to McAllen, Texas.
Approximately 500 soldiers from the 10th Mountain Division will support the mission at Fort Huachuca, Arizona, the headquarters for JTF–Southern Border. In total, about 10,000 service members now support the southern border mission.
Other units supporting the mission include:
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2nd Brigade, 4th Infantry Division
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101st Division Sustainment Brigade
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264th Combat Sustainment Support Battalion, 3rd Expeditionary Sustainment Command
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90th Sustainment Brigade
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89th Military Police Brigade
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3rd Combat Aviation Brigade, 3rd Infantry Division
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1st Combat Engineer Battalion, 1st Marine Division
Prior to the emergency declaration, about 2,500 service members were already assigned to the southern border. Over the past 60 days, troop levels have increased by approximately 7,500.
To accommodate this growth, some units are relocating along the border. Rather than placing incoming units within an existing unit’s area of operations, JTF–Southern Border is realigning responsibilities among subordinate commands. This allows command elements to operate in adjacent regions, reducing geographic dispersion and enhancing command and control.
Moving 2,500 service members, along with their equipment and personal gear, is a significant logistical undertaking. These moves are timed with the arrival of new units and require coordination to ensure proper hand-offs. While the operation is complex, it will enhance efficiency once fully implemented. Throughout the transition, JTF–Southern Border continues to support CBP.
The transfer of authority and surge in deployed capabilities demonstrate the Department of Defense’s continued commitment to supporting DHS and achieving full operational control of the southern border.