“There are mountains. There’s rivers. There’s a lot of natural boundaries that we have right now that is going to make it very difficult to put a fence or a wall,” Cuellar told CNN’s “New Day.”
“Second of all, in Texas, most of the private property that we have in the southwest border is in the state of Texas," the congressman said. "There will be lawsuits that will delay the building of any fence.”
Cuellar represents the 28th Congressional District in the Lone Star State, which includes the San Antonio suburbs and stretches to the U.S.-Mexico border.
Cuellar instead recommended “strategic fencing," adding that current practices, like electronic surveillance, are also useful.
Cuellar said the United States should be working with Mexico on border issues.
“We need to extend it to the 20-yard line and work with those friends across the border," Cuellar added.
Trump last month signed an executive order calling for the construction of the border wall, a signature campaign promises for which he has vowed Mexico will pay.
Mexican President Enrique Peña Nieto has said multiple times that his country will not foot the bill for the wall.
Trump said last month that Mexico will likely reimburse the United States for the cost of the wall, arguing that doing so would allow the wall to be built sooner rather than later.