"If Trump were ever elected, we'd have to build a wall around California to defend ourselves from the rest of this country," he said Monday at a dinner with the California Labor Federation and State Building and Construction Trades Council in Sacramento. "By the way, that is a joke. We don't like walls; we like bridges."

This isn't the first time Brown, 77, has taken a dig at Trump's plans for a wall along the U.S.-Mexico border. Brown recently told Bloomberg that Trump's idea is "absolutely preposterous."

"It would create such tension with our closest neighbor that, probably, a dumber idea I can't imagine," Brown said.

"Some of these old white guys ought to recognize that the whole pension system would collapse if we didn't have a bunch of young people coming into this country and into this state," he said, according to KNSD-TV. "They're not all coming from here. They're coming from other places."