A section of the US–Mexico border fence at San Luis Rio Colorado, Sonora state, on February 15, 2017, in northwestern Mexico. #

A man walks next to the Mexico–US border at Playas de Tijuana in northwestern Mexico on February 13, 2017. #

A stream of tail lights illuminate the road as cars cross the border into Mexico from San Diego, California,, on February 13, 2017. #

An abandoned sofa sits against the border fence on the US–Mexico border in Tecate, California on February 14, 2017. #

A construction crew works near the border fence on the US–Mexico border at the Imperial Sand Dunes in Dunes, California, on February 15, 2017. #

An old wheelchair sits in the middle of the desert near the border fence in Winterhaven, California, on February 15, 2017. #

Mexican soldiers drive along a section of the US–Mexico border fence in Sonoyta, on February 16, 2017, in northwestern Mexico. #

A section of the border fence on the US–Mexico border in Agua Prieta, Sonora, on February 18, 2017, in northwestern Mexico. #

An old pay phone box hangs on the wall of an abandoned grocery store next to the border fence on the US–Mexico border in Del Rio, Texas, on February 21, 2017. #

A US Border Patrol fan boat on the the Rio Grande river on the US–Mexico border in Eagle Pass, Texas, on February 21, 2017. #

A temporary agricultural worker poses for a picture as she returns to the Port of Entry in San Luis, Arizona, on February 15, 2017. #

A sign warns against illegal smuggling in Organ Pipe Cactus National Monument near Lukeville, Arizona, on February 16, 2017. #

A section of the border fence in Agua Prieta, Sonora, Mexico, on February 18, 2017. #

A section of the border fence in Nogales, Arizona, on February 17, 2017. #

A migrant oasis filled with water and candles stands just off the road in Bisbee, Arizona, on February 18, 2017. #

A section of the border fence is interrupted outside of Sunland Park, New Mexico, on February 19, 2017. #

The Douglas, Arizona, border crossing, seen from Agua Prieta, Sonora, Mexico, on February 18, 2017. #

US Border Patrol agents speak with a woman on the border in El Paso, Texas, on February 20, 2017, prior to her crossing into the US. #

The bridge from Eagle Pass, Texas, to Piedras Negras, Mexico, photographed on February 21, 2017. #

A US Border Patrol Tethered Aerostat Radar System (TARS) blimp floats in the air near the border outside Eagle Pass, Texas, on February 22, 2017. #

84-year-old Trinidad sits at a plaza on the border in Piedras Negras, Mexico, on February 21, 2017. #

A barrel with water stands on a dirt road near the US–Mexico border outside Eagle Pass, Texas, on February 22, 2017. #

The border fence ends abruptly near the town limit of Del Rio, Texas, on February 21, 2017. #

Sculptures stand on the international boundary at Amistad Reservoir on the US–Mexico border near Ciudad Acuna, Mexico, on February 21, 2017. #