WASHINGTON: The Pentagon said Wednesday it has begun deploying 1,500 active duty troops to help secure the southern border in the coming days, putting in motion plans President Donald Trump laid out in executive orders shortly after he took office to crack down on immigration.
Acting Defense Secretary Robert Salesses said the Pentagon will provide military aircraft to support Department of Homeland Security deportation flights for more than 5,000 detained migrants and the troops will assist in the construction of barriers.
The number of troops and their mission may soon change, Salesses said in a statement. “This is just the beginning,” he said.
It remains to be seen if they will end up doing law enforcement, which would put American troops in a dramatically different role for the first time in decades.
The active duty forces will join the roughly 2,500 US National Guard and Reserve forces already there. There are currently no active duty troops working along the roughly 2,000-mile border.
Personnel started moving to the border earlier Wednesday, according to a military official briefing reporters on the condition of anonymity to provide additional details on the deployment. The troops will include 500 Marines from Camp Pendleton in California, and the remainder will be Army.
Troops have done similar duties in support of Border Patrol agents in the past, when both Trump and former President Joe Biden sent active duty troops to the border.
Troops are prohibited by law from doing law enforcement duties under the Posse Comitatus Act, but that may change. Trump has directed through executive order that the incoming secretary of defense and incoming homeland security chief report back within 90 days if they think an 1807 law called the Insurrection Act should be invoked. That would allow those troops to be used in civilian law enforcement on US soil.
The last time the act was invoked was in 1992 during rioting in Los Angeles in protest of the acquittal of four police officers charged with beating Rodney King.
The widely expected deployment, coming in Trump’s first week in office, was an early step in his long-touted plan to expand the use of the military along the border. In one of his first orders on Monday, Trump directed the defense secretary to come up with a plan to “seal the borders” and repel “unlawful mass migration.”
“This is something President Trump campaigned on,” said Karoline Leavitt, White House press secretary. “The American people have been waiting for such a time as this — for our Department of Defense to actually implement homeland security seriously. This is a No. 1 priority for the American people.”
On Tuesday, just as Trump fired the Coast Guard commandant, Adm. Linda Fagan, the service announced it was surging more cutter ships, aircraft and personnel to the “Gulf of America” — a nod to the president’s directive to rename the Gulf of Mexico.
Trump said during his inaugural address on Monday that “I will declare a national emergency at our southern border. All illegal entry will immediately be halted, and we will begin the process of returning millions and millions of criminal aliens back to the places in which they came.”
Military personnel have been sent to the border almost continuously since the 1990s to help address migration. drug trafficking and transnational crime.
In executive orders signed Monday, Trump suggested the military would help the Department of Homeland Security with “detention space, transportation (including aircraft), and other logistics services.”
There are about 20,000 Border Patrol agents, and while the southern border is where most are located, they’re also responsible for protecting the northern border with Canada. Usually agents are tasked with looking for drug smugglers or people trying to enter the country undetected.
More recently, however, they have had to deal with migrants actively seeking out Border Patrol in order to get refuge in America — taxing the agency’s staff.
In his first term, Trump ordered active duty troops to the border in response to a caravan of migrants slowly making its way through Mexico toward the United States in 2018. More than 7,000 active duty troops were sent to Texas, Arizona and California, including military police, an assault helicopter battalion, various communications, medical and headquarters units, combat engineers, planners and public affairs units.
At the time, the Pentagon was adamant that active duty troops would not do law enforcement. So they spent much of their time transporting Border Patrol agents to and along the border, helping them erect additional vehicle barriers and fencing along the border, assisting them with communications and providing some security for border agent camps.
The military also provided Border Patrol agents with medical care, pre-packaged meals and temporary housing.
It’s also not yet clear if the Trump administration will order the military to use bases to house detained migrants.
Bases previously have been used for that purpose, and after the 2021 fall of Kabul to the Taliban, they were used to host thousands of Afghan evacuees. The facilities struggled to support the influx.
In 2018, then-Defense Secretary Jim Mattis ordered Goodfellow Air Force Base in San Angelo, Texas, to prepare to house as many as 20,000 unaccompanied migrant children, but the additional space ultimately wasn’t needed and Goodfellow was determined not to have the infrastructure necessary to support the surge.
In March 2021, the Biden administration greenlighted using property at Fort Bliss, Texas, for a detention facility to provide beds for up to 10,000 unaccompanied migrant children as border crossings increased from Mexico.
The facility, operated by DHS, was quickly overrun, with far too few case managers for the thousands of children that arrived, exposure to extreme weather and dust and unsanitary conditions, a 2022 inspector general report found.

The Trump administration has put a freeze on many federal health agency communications with the public through at least the end of the month.
In a memo obtained by The Associated Press, acting Secretary of the US Department of Health and Human Services Dorothy Fink told agency staff leaders Tuesday that an “immediate pause” had been ordered on — among other things — regulations, guidance, announcements, press releases, social media posts and website posts until such communications had been approved by a political appointee.
The pause also applies to anything intended to be published in the Federal Register, where the executive branch communicates rules and regulations, and the Morbidity and Mortality Weekly Report, a Centers for Disease Control and Prevention scientific publication.
The pause is in effect through Feb. 1, the memo said. Agencies subject to the HHS directive include the CDC, the National Institutes of Health and the Food and Drug Administration — entities that fight epidemics, protect the nation’s food supply and search for cures to diseases.
HHS officials did not respond to requests for comment on the pause, which was first reported by The Washington Post. Four federal health officials speaking on condition of anonymity because they weren’t authorized to discuss the issue confirmed the communication pause to the AP.
A former HHS official said Wednesday that it’s not unusual for incoming administrations to pause agency communications for review. But typically, officials working on the president’s transition team have the process for issuing documents running smoothly by inauguration day.
“The executive branch is a hierarchy,” said Steven Grossman, who now consults for food and drug companies, in an email. “Whether stated publicly or not, every new administration wants important commitments and positions to wait until new teams are in place and some semblance of hierarchy restored.”
A pause is reasonable as a changing executive branch takes steps to become coordinated, said Dr. Ali Khan, a former CDC outbreak investigator who is now dean of the University of Nebraska’s public health college.
“The only concern would be is if this is a prelude to going back to a prior approach of silencing the agencies around a political narrative,” he added.
During his first term, President Donald Trump’s political appointees tried to gain control over the CDC’s MMWR journal, which had published information about the COVID-19 pandemic that conflicted with messaging from the White House.
Fink wrote in her memo that some exceptions would be made for communications affecting “critical health, safety, environmental, financial or nation security functions,” but that those would be subject to review. The FDA on Tuesday and Wednesday posted notices about warning letters sent to companies and a drug safety notice.
A consumer advocacy group said the communications pause could still threaten public safety.
Americans depend on timely information from the CDC, the FDA and other agencies to avoid foodborne illnesses and stay aware of other health issues, said Dr. Peter Lurie, president of the Center for Science in the Public Interest.
“When it comes to stopping outbreaks, every second counts,” Lurie said in a statement. “Confusion around the vaguely worded gag order is likely to lead to unnecessary delay in publishing urgent public alerts during active outbreaks.”
He was echoed by Dr. Jeffrey Klausner, a University of Southern California public health expert.
“Local health officials and doctors depend on the CDC to get disease updates, timely prevention, testing and treatment guidelines and information about outbreaks,” Klausner wrote in an email. “Shutting down public health communication stops a basic function of public health. Imagine if the government turned off fire sirens or other warning systems.”