The Defense Department is likely to meet a request from the Department of Homeland Security on Friday to extend the deployment of thousands of active-duty troops to the border through the end of January.
The deployment for the more than 5,700 troops was initially projected to end Dec. 15, but the DoD said in a statement Friday that DHS had asked the military to "extend its support through January 31."
The DoD statement said the extension is necessary to assist Customs and Border Protection (CBP) in meeting the "current threat" from thousands of migrant asylum seekers massing in Tijuana.
Defense Secretary Jim Mattis is expected to sign the DHS request for assistance this weekend, according to Pentagon officials. At the same time, he is expected to order that the number of active-duty troops deployed to the border be reduced to about 4,000.
The active-duty troops began deploying to the border late last month, in line with President Donald Trump's demand to stop the "caravans" of migrants seeking to enter the U.S. In addition, about 2,100 National Guard troops have been on the border since last April.
The active-duty troops were deployed to Texas, Arizona and California, but not New Mexico. Beginning last week, about 300, including military police and engineers, were shifted to California to assist CBP at the San Ysidro, California, port of entry across from Tijuana.
Under federal law, the troops are limited to assisting CBP with communications, intelligence and transportation. They have no arrest or detention authorities. The troops have also been stringing concertina wire at vulnerable crossing points and shoring up barricades at ports of entry.
Last week, Mattis told defense reporters that the troops would continue to be unarmed but might wear shields and carry batons in situations where they had to come to the aid of a CBP agent who was under attack.
Trump critics have called the deployments a "political stunt" that was aimed at helping Republicans in the November elections, but Mattis has defended them, saying they are similar to previous border deployments in the administrations of Democrats and Republicans.
Earlier this month, the commander of the deployed active-duty troops, Lt. Gen. Jeffrey Buchanan of Army North, suggested they might all be home for Christmas.
"We'll continue to support CBP's request for support up until Dec. 15, unless we're directed otherwise," he said.
But the latest request from DHS appears to have scrapped that plan.
-- Richard Sisk can be reached at Richard.Sisk@Military.com.
