An internal Border Patrol memo obtained by ABC News indicates that the Department of Homeland Security may request up to 10,000 U.S. troops to assist in the effort. United States-Mexico border
Defense officials, however, said this week that they did not know that figure, but said they expected there could be additional requests for troops.
“This is just the beginning. This is an initial step, and we have many more missions planned,” a senior Defense official told reporters.
The White House announced yesterday that it will send 1,500 troops to support operations on the southern border. Those duties, according to the sources, would be to assist in processing and surveillance.

National Guard troops operate an airship on the Rio Grande River between Piedras Negras, Coahuila, Mexico and Eagle Pass, Texas on January 17, 2025.
Cheney Page/Reuters
Customs and Border Protection’s planning memo also says the agency could request military infrastructure and technology.
CBP may use “military bases” as safe havens for those detained by Customs and Border Protection. Defense officials said the DOD had not received any requests for that type of assistance, but would evaluate those requests.
The the army According to the document, it can also help enforce and conduct coastal border operations.
Two U.S. officials told ABC News on Thursday afternoon that the first of the 500 Marines heading to the border would be sent in the coming hours. the army the units would be transported on the same day. A large number of Army troops will serve as military police, but will not perform law enforcement duties, according to other officials.
In addition, four military cargo planes are being deployed for use on deportation flights: a C-17 and C-130 in San Diego and another C-17 and C-130 in Fort Bliss, Texas. So far from C-17 to Ft. Deportation flights cannot begin until the State Department arranges the details, which may take some time.

A drone view of National Guard troops resting on the banks of the Rio Grande River in Eagle Pass, Texas, outside Shelby Park on January 17, 2025.
Cheney Page/Reuters
The US Northern Command said in a news release Thursday that it is “aggressively” strengthening border security. About 1,500 soldiers and Marines are being deployed “immediately” to the region to supplement the roughly 2,500 service members already stationed at CBP’s border.
“In a few days, we will nearly double the number of forces along the border, effectively implementing the president’s intent while planning and deploying a broader effort to protect the sovereignty and territorial integrity of the United States,” said General Gregory M. Guillot, commander of the Northern Command.
The exact number of personnel will vary as units rotate personnel and as additional forces deploy as planning efforts are completed, Northern Command said. These forces will enhance detection and monitoring efforts and repair and install physical barriers, the statement said.
-ABC News’ Matt Seyler contributed to this report.