mexico-u.s. border

Sen. Mike Lee, a Republican from Utah, traveled to Mexico City on March 20 with the U.S. congressional delegation to meet with Mexican President Andrés Manuel López Obrador and members of his administration.

In this April 10, 2018 frame from video, a National Guard troop watches over Rio Grande River on the border in Roma, Texas. The deployment of National Guard members to the U.S.-Mexico border at President Donald Trump's request was underway Tuesday with a gradual ramp-up of troops under orders to help curb illegal immigration. (AP Photo/John Mone)

In this Monday, June 5, 2006, file photo, Utah National Guard troops from the 116th Construction Equipment Support Company, the first National Guard unit along the border as part of Operation Jump Start, prepare to extend a wall along the U.S.-Mexico border in San Luis, Ariz. In 2018, the U.S. National Guard faces a vastly different environment than it did on its last two deployments to the border with Mexico, with far fewer illegal crossings and more Central Americans than Mexicans coming. (AP Photo/Khampha Bouaphanh, File)