President Trump arrives in California to inspect border wall prototypes

He'll also deliver remarks to U.S. troops.

Ahead of his arrival, the president tweeted that "thousands of dangerous, violent criminal aliens are released" as a result of California's immigration sanctuary policies.

Standing alongside one of the prototypes, Trump said tall walls were needed to keep out “incredible climbers.”

“Getting over the top is easy. These are like professional mountain climbers, these are incredible climbers,” Trump said. “They can't climb some of these walls, some of them they can.”

"You see in California we are focusing on bridges, not walls," Brown said. "After you've examined your wall prototypes on the border, I invite you to head north to the Central Valley -- the heart of California. Here in cities like Fresno and Madera more than a dozen bridges and viaducts are being built for the nation's first and only High-Speed Rail line."

Trump responded to the criticism from Brown, accusing him of making residents less safe over sanctuary city policies and sky-high taxes.

“I think the governor's doing a terrible job running the state of California,” Trump said. “I have property in California I will say, I don't speak too much about my property any more. The taxes are way, way out of whack and people are going to start to move pretty soon.”

Construction of the eight wall prototypes in the San Diego area were completed in October of last year. Six companies were chosen to build eight sample walls -- four made of concrete and four of other materials -- according to U.S. Customs and Border Protection.

ABC's Geneva Sands contributed reporting to this story.