This article originally appeared on ARCHITECT.

Photo by Mani Albrecht for U.S. CBP

In his first visit to California since taking office, President Donald Trump traveled to San Diego on Tuesday to survey the eight 30-foot borderwall prototypes commissioned by the Department of Homeland security last year. During the meeting, Trump told reporters, "you have to have see-through," referring to the barriers. "You have to know what's on the other side of the wall."

This is the latest demand made by the president as he renews his request for $18 billion in appropriations from Congress for the construction of the borderwall. As part of the trip, Trump also tweeted, "If we don’t have a wall system, we’re not going to have a country," and again called for Congress to restrict funding to sanctuary cities.

Read more of ARCHITECT's borderwall coverage here.