Migrants won't see armed soldiers on border

FILE - In this Sunday, Nov. 4, 2018 file photo, members of a U.S Army engineering brigade place concertina wire around an encampment for troops, Department of Defense and U.S. Customs and Border Protection personnel near the U.S.-Mexico International bridge in Donna, Texas. (AP Photo/Eric Gay)

As thousands of migrants in a caravan of Central American asylum-seekers converge on the doorstep of the United States, what they won't find are armed American soldiers standing guard.

Instead they will see cranes installing towering panels of metal bars and troops wrapping concertina wire around barriers while military helicopters fly overhead, carrying border patrol agents to and from locations along the U.S.-Mexico border.

That's because U.S. military troops are prohibited from carrying out law enforcement duties.

What's more, the bulk of the troops are in Texas — hundreds of miles away from the caravan that started arriving this week in Tijuana on Mexico's border with California after walking and hitching rides for the past month.