Gen. John F. Kelly, President-elect Donald Trump's nominee for Homeland Security secretary, said during his confirmation hearing on Tuesday that a proposed border wall alone will not stop all illegal immigration.
Building a wall along the U.S.-Mexico border has been a major Trump campaign theme, but it was derided by opponents, including some Republicans.
Arizona Sen. John McCain told Kelly that while the nation does need barriers, "building a wall is not the way to prevent the flow of drugs or people illegally across the border." He suggested drones and towers to help monitor the southern border.
"A physical barrier in and of itself, as a military person that understands defense and defenses . . . will not do the job," Kelly replied, suggesting instead a "layered defense."
"If you were to build a wall from the Pacific to the Gulf of Mexico, you would still have to back that wall up with patrolling by human beings, sensors, observation devices," Kelly said.
He reiterated his belief that he said he has shared with senators for years that the defense of the border "starts about 1,500 miles south," partnering with countries such as Peru and Mexico to fight the illegal drug trade.
"I think we can work closely with them, give them more of what they need," Kelly said. "We certainly share intel with them, information with them now."
McCain said morale among Border Patrol agents is low, and suggested Kelly spend time with them.
"I think you know from your leadership experiences that if the morale of your force is not good then it's hard to get the mission accomplished," McCain said.