Acting Homeland Security Secretary Elaine Duke said Tuesday that the border wall at the Yuma, Arizona sector of the border shows that border walls work, just hours before Trump was set to visit there.

“Our Border Patrol agents have seen firsthand the success of a border wall in Yuma, Ariz. — which serves as a prime example of how investments in personnel, technology and a border wall can turn the tide against a flood of illegal immigration and secure our homeland,” Duke wrote in an op-ed for USA Today called “Border walls work. Yuma sector proves it.”