ARI SHAPIRO, HOST:
The first Central American caravan of migrants traveling toward the U.S. has stopped. It's been moving north across Mexico for a month. More than 2,500 people are now in Tijuana, just south of San Diego. And another 3,500 are also headed that way from the border town of Mexicali to the east. That's causing tension with some of the people who live in those cities. And it's also a growing concern among U.S. officials on this side of the border.
NPR Pentagon correspondent Tom Bowman has been following the deployment of active duty troops to the border and joins us now. Hi, Tom.
TOM BOWMAN, BYLINE: Hey, Ari.
SHAPIRO: These troops have been in place at the border for about 10 days. What have they been doing?
BOWMAN: Well, first of all, there are about 5,900 soldiers and Marines all along the border. They've been setting up tents, reinforcing fences along border entry points. And they're in support of border police and the Department of Homeland Security.
Defense Secretary Jim Mattis visited them last week at a camp outside McAllen, Texas. And one soldier asked if they'll be taking down the razor wire at some point. And Mattis said, we'll let you know.
SHAPIRO: These are active duty troops, so they're limited in what they can actually do. Tell us about what those limitations are.
BOWMAN: Right, and again, it's simply support, shoring up fences and so forth. But they have no law enforcement role. They're barred from that role because of a 19th century act called Posse Comitatus, which prohibits the military from getting involved in any law enforcement duties. So that's all up to border police.
SHAPIRO: Who are these troops reporting to? Who's actually in command there?
BOWMAN: Well, the commanding general is Army Lieutenant General Jeff Buchanan. And, Ari, what's unusual here is, again, you have about 6,000 active duty troops. And in past decades, it's almost always National Guard troops that help the border police along the border for drug interdiction or refugees coming across. And some I talk with in the Pentagon are kind of scratching their heads over there. They're saying, listen; there are already 2,100 National Guard troops along the border. There is really no need for these thousands of active troops.
And that's led to some on Capitol Hill and some retired military folks to say this is all a serious waste of money and clearly a political stunt by President Trump, who ordered these troops down to the border right before the midterm elections.
SHAPIRO: Is the mission there on the border changing as more migrants arrive?
BOWMAN: Well, we've been hearing that - at the Pentagon, that President Trump may expand authorities for the troops to essentially, let's say, come to the aid of border police if there's, let's say, a breach in the border fence and violence ensues. But at this point, there's absolutely no indication now of any violence. There are hundreds more people arriving in Tijuana, Mexico, right on the border and seeking asylum in the U.S. Many more are expected to come. There are protests by Tijuana residents about these folks coming in but no sense at this point of any real problems, any violence really at all at this point.
SHAPIRO: This was never supposed to be a long-term deployment. It was scheduled to end on December 15. Is there any chance that the deployment could be extended? What's the road ahead?
BOWMAN: Well, we don't really know right yet. I was talking with one Pentagon official who said, you know, it's a possibility this deployment of troops could extend past December 15 - but no word on that yet. General Buchanan was talking to reporters, and he said he may send home some of his troops, some of the engineering support and so forth. But at this point, again, no sense of any - any troops actually heading home.
And we also don't think there'll be any additional troops heading there. At one point, Defense Secretary Mattis said, you know, we could send more troops. But at this point, it looks like it's going to stick at roughly the 5,900 troops. And actually tonight, those troops, the cost of them - the Pentagon just put out tonight the cost of this deployment of 5,900 troops through December 15 - $72 million.
SHAPIRO: Seventy-two million dollars - all right, NPR Pentagon correspondent Tom Bowman - thanks so much, Tom.
BOWMAN: You're welcome, Ari. Transcript provided by NPR, Copyright NPR.