Military personnel began arriving in El Paso, Texas, and San Diego, California, on Thursday evening, after President Donald Trump’s declaration of a national emergency at the southern border. The additional 1,500 active-duty forces include 1,000 US Army personnel and 500 Marines from Camp Pendleton in California, who will be assigned near the border upon arrival. “This represents a 60% increase in active-duty ground forces since President Trump was sworn in on Monday,” Acting Defense Secretary Robert Salesses said in a statement late Wednesday.

There are already 2,500 US service men stationed along the southern border. According to a spokesperson for the United States Northern Command, the troops were dispatched there in May 2023 under the Biden administration under Title 10 authorities approved by former Defense Secretary Lloyd Austin and are expected to stay until the end of Fiscal Year 2025. According to a statement from the National Guard Bureau of Public Affairs, the National Guard is also increasing its support and coordinating emergent requirements with USNORTHCOM and US Transportation Command for additional personnel, military airlift, barrier construction, and other capabilities in order to meet presidential and Secretary of Defense directives.

“The National Guard currently has over 1,600 Guardsmen supporting the federal border security mission,” said Gen. Steven S. Nordhaus, director of the National Guard Bureau. “In conjunction with our Joint Service partners, we are developing additional support options to meet USNORTHCOM, USTRANSCOM and Department of Homeland Security force requirements as this critical mission evolves.” Additionally, more than 4,100 Texas National Guard members are still on duty at the border to support continuing Operation Lone Star efforts.

Some of the troops deployed to the southern border were on call or actively working in support of the California wildfires, but they were released from that duty and are now being reallocated, according to the senior official.