Customs and Border Protection closed three lanes of traffic heading into the United States from Mexico Tuesday morning.
In a statement, CBP said it was “to install and pre-position port hardening infrastructure equipment in preparation for the migrant caravan.”
One lane of traffic was also closed at the Otay Mesa port of entry.
It comes as active-duty troops have been working to add barricades and fencing as part of “Operation Secure Line.”
On Tuesday, troops could be seen moving barriers covered with barbed wire along the border, periodically closing the southbound lanes into Mexico.
In their statement, CBP officials warned “persons traveling northbound to the U.S. anticipate possible increased wait times because of the lane closures.”
Even before the lanes were closed, wait times of six to seven hours had been reported at peak times in the standard lanes. Part of that was due to traffic control by authorities on the Mexican side.
Travel as a pedestrian, however, has not appeared to be affected.
Rebecca Fodor walked across Tuesday night and said it only took a few minutes. She said she did notice armed troops in camouflage uniforms.
“It didn’t really change anything. I think they were just watching for anything suspicious,” she said.
The lane closures will remain in effect indefinitely. CBP says reopening “is not anticipated to take place until sometime after people in the caravan arrive to the border.”