What to Know
In mid-October, a caravan of at least 3,500 Central American migrants seeking asylum left Honduras for the United States border.
A Pentagon risk assessment found that the caravan did not pose a threat to the United States, according to a person with direct knowledge.
The move to deploy troops to the U.S.-Mexico border is shaping up to cost $220 million, according to two U.S. defense officials.
More than a thousand U.S. Marines from Camp Pendleton have been deployed the U.S.-Mexico border south of San Diego Thursday, a U.S. Marines spokesperson confirmed.
Official U.S. military vehicles used to transport troops were spotted near the pedestrian crossing at the San Ysidro Port of Entry.
NBC 7 has learned 1,100 Marines are beginning their work with Operation Secure Line in support of the U.S. Customs and Border Protection.
The Marines are part of Special-Purpose Marine Air-Ground Task Force 7, 1st MEF, according to the Pentagon.
“We are putting up concertina wire to help make the wall less scalable,” said Lieutenant Fredrick D. Walker, public information officer for the Special Purpose Marine Air-Ground Task Force. “We’re here to support our friends at Custom and Border Protection.”
NBC 7 crews got a tour of operations Thursday morning, where marines were hard at work setting up barbed wire.
Locals who walk along the border daily to get to work could see the stationed troops from a San Ysidro bridge nearby.
"I think it's alright because it's for the United States security," said Jose Plascencia, who shops across the border.
But for Lesley Sandoval of National City, the sight of the troops was concerning.
"To me, it's insane," said Sandoval. "The people [on the migrant caravan] are probably not going to bring guns, they are trying to have an opportunity to live here."
The troops will also be used to reinforce staffing in the event large groups move to cross the border into the U.S., CBP officials said in a prepared statement.
The Department of Defense estimates that more than 7,000 troops will be positioned in California, Arizona and Texas in support of the Department of Homeland Security and Customs and Border Protection.
There are currently 5,600 troops spread out across the three states, the marines confirmed Thursday.
The troops included in the deployment are from Fort Carson, Colorado; Fort Detrick, Maryland; Fort Hood, Texas; Fort Knox, Kentucky; Fort Meade, Maryland; Fort Riley, Kansas; Fort Stewart and Hunter Army Airfield, Georgia; Joint Base Charleston, South Carolina; Joint Base Lewis-McChord, Washington;U.S. Transportation Command; Joint Base San Antonio, Texas, Fort Bliss, Texas; Fort Bragg, North Carolina; Fort Campbell, Kentucky, Naval Station Norfolk, Virginia; and Peterson Air Force, Colorado.
The border mission will have a larger U.S. military footprint than the combined efforts in Iraq and Syria.
The Department of Defense estimates that ultimately over 7,000 troops may be deployed to the southern border.
The White House has said the U.S. may send up to 15,000 troops to the border in order to deter a caravan of Central American migrants that is moving north from Honduras through Mexico.
At one point, the United Nations estimated there were 7,200 people in the caravan.