Camp Pendleton Marines were at the Imperial Beach Station Friday as part of a new border deployment ordered by President Donald Trump.
About 500 sailors and Marines from the base are among the 1,500 troops ordered to the border Wednesday, a Marine spokesperson said. They join about 2,500 troops already deployed to the border to assist U.S. Customs and Border Protection.
Active duty troops are barred by law from conducting law enforcement within the U.S., which limits them to a supporting role.
The border mission is led by U.S. Northern Command, which is responsible for military operations in the continental U.S.
This week's deployment is just the initial phase of the operation, U.S. Northern Command said in a statement Thursday.
"The exact number of personnel will fluctuate as units rotate personnel and as additional forces are tasked to deploy once planning efforts are finalized," the statement said. "These military forces will support enhanced detection and monitoring efforts and repair and emplace physical barriers."
Most of the 1,500 troops are U.S. Army soldiers deploying from bases throughout the U.S., according to a statement from Northern Command Friday.
The sailors and Marines are from the 1st Combat Engineer Battalion and the 7th Engineering Support Battalion.
This isn't the first time active duty troops have deployed to the border under orders from Trump.
During his first term, Trump ordered about 5,000 troops to the border just ahead of the 2018 midterm elections.
That deployment included about 1,100 troops from Camp Pendleton.
