FOTOS: Autoridades fronterizas advierten a caravana migrante: Deben obedecer la ley

Pete Flores, Director of Field Operations for the San Ysidro Port of Entry, left, dark uniform, greeted Lieutenant General Jeffrey S. Buchanan, Commanding General, US Army North, third from left, facing Flores, before they set out on foot for a tour of work being done to fortify the border.   (John Gibbins / San Diego Union-Tribune)

A Marine attached concertina wire along a wall by the southbound pedestrian walkway in to Mexico.  (John Gibbins / San Diego Union-Tribune)

Marines from the 7th Engineering Support Battalion from Camp Pendleton, Ca., worked just east of the San Ysidro Port of Entry worked to “harden” the border in support of Operation Secure Line, which was ordered by President Trump, fearing an “invasion” of immigrants coming to the border from Central American countries.   (John Gibbins / San Diego Union-Tribune)

Marines from the 7th Engineering Support Battalion from Camp Pendleton, Ca., worked just east of the San Ysidro Port of Entry worked to “harden” the border in support of Operation Secure Line, which was ordered by President Trump, fearing an “invasion” of immigrants coming to the border from Central American countries.   (John Gibbins / San Diego Union-Tribune)

An entourage of Border Patrol and Military leaders walked away from the boreder fence after taking a look at activities to “harden” the border in support of Operation Secure Line, which was ordered by President Trump, fearing an “invasion” of immigrants coming to the border from Central American countries.   (John Gibbins / San Diego Union-Tribune)

Marines from the 7th Engineering Support Battalion from Camp Pendleton, Ca., strung out concertina wire just east of the San Ysidro Port of Entry worked to “harden” the border in support of Operation Secure Line, which was ordered by President Trump, fearing an “invasion” of immigrants coming to the border from Central American countries.  (John Gibbins / San Diego Union-Tribune)

A Marine worked on his computer as Marines from the 7th Engineering Support Battalion from Camp Pendleton, Ca., worked just east of the San Ysidro Port of Entry worked to “harden” the border in support of Operation Secure Line, which was ordered by President Trump, fearing an “invasion” of immigrants coming to the border from Central American countries.   (John Gibbins / San Diego Union-Tribune)

Marines from the 7th Engineering Support Battalion from Camp Pendleton, Ca., worked just east of the San Ysidro Port of Entry worked to “harden” the border in support of Operation Secure Line, which was ordered by President Trump, fearing an “invasion” of immigrants coming to the border from Central American countries.   (John Gibbins / San Diego Union-Tribune)

During a tour of the San Ysidro Port of Entry, a traveler presented himself to an inspector for entry in to the country.   (John Gibbins / San Diego Union-Tribune)

During a tour of the San Ysidro Port of Entry, a traveler presented himself to an inspector for entry in to the country.  (John Gibbins / San Diego Union-Tribune)

A family who had presented themselves to claim asylum was processed at the San Ysidro port of entry.   (John Gibbins / San Diego Union-Tribune)

A man who had presented himself for claim asylum was processed at the San Ysidro port of entry.   (John Gibbins / San Diego Union-Tribune)

A line of asylum seekers waited in line inside the San Ysidro Port of Entry.   (John Gibbins / San Diego Union-Tribune)

Pedestrians moved towards the gates as they made their way through the new pedestrian port of entry.   (John Gibbins / San Diego Union-Tribune)

The American flag flew over the San Ysidro Port of Entry.   (John Gibbins / San Diego Union-Tribune)

A K-9 officer and dog worked the vehicle line as vehicles waited to cross in tot he United States.   (John Gibbins / San Diego Union-Tribune)

A CBP agent demonstrated how her drug sniffing dog named Mary worked in the secondary inspection area of the San Ysidro Port of Entry.   (John Gibbins / San Diego Union-Tribune)

Pete Flores, Director of Field Operations for the San Ysidro Port of Entry, spoke to the media during a press conference about the northbound caravan of migrants seeking asylum in the US.   (John Gibbins / San Diego Union-Tribune)

Seal of the Department of Homeland Security   (John Gibbins / San Diego Union-Tribune)

During a tour of the San Ysidro Port of Entry. during a joint press conference that included Pete Flores, Director of Field Operations for the San Ysidro Port of Entry, second from left, Rodney Scott, chief Patrol Agent for Border Patrol San Diego Sector, far left, Hunter Davis, Director of Air and Marine Operations San Diego for Border Patrol, far right, and Lieutenant General Jeffrey S. Buchanan, Commanding General, US Army North, at podium.   (John Gibbins / San Diego Union-Tribune)

Lieutenant General Jeffrey S. Buchanan, Commanding General, US Army North spoke to the media during a press conference at the San Ysidro Port of Entry.   (John Gibbins / San Diego Union-Tribune)