March 13 (UPI) -- President Donald Trump visited California on Tuesday to view prototypes for a proposed U.S.-Mexican border wall, saying it's the first line of defense to undocumented immigration, though he prefers one that is "see-through."
It was Trump's first visit to the state since his inauguration. His first stop was was to view the prototypes for a border wall he says would be critical for the nation's security.
"If you don't have a wall system ... we're not gonna have a country," he said.
Trump called on Congress to approve funding for the wall while at the same time halting federal grants to cities with sanctuary policies.
"The border wall is truly our first line of defense," he said, adding that sanctuary jurisdictions are the "best friend of the criminal."
He took issue with California's support for sanctuary policies, saying Gov. Jerry Brown has "done a very poor job running California." The mayor of Oakland, Calif., Libby Schaaf, also drew the president's ire after she warned undocumented immigrants of a planned federal immigration raid last month.
"Sanctuary cities are protecting a horrible group of people in many cases -- criminals -- and what happened as an example in Oakland was a disgrace to our nation and we just can't let that happen," Trump said.
Viewing the eight prototypes, Trump said he'd prefer a see-through wall.
"You have to know what's on the other side of the wall," he said, adding that the wall should be built so that no one can climb it.
"These are like professional mountain climbers. They're incredible climbers. They can't climb some of these walls," Trump said of immigrants.