Steve Bannon warned Friday evening that California might pose a "problem" to the U.S. by attempting to secede.

Couching his statement on California's status as a "sanctuary state," Bannon, President Trump's former chief strategist, contended that California's Democrats and "the lords of Silicon Valley" would attempt to flee like states did in the run-up to the Civil War if the policy isn't turned around.

"You are a sanctuary state," he told a crowd in Anaheim at the California Republican Party convention. "If you do not roll this back, 10 or 15 years from now the folks in Silicon Valley and progressive Democrats are going to try to secede from the union."

The issue of secession was settled 150 years ago, Bannon contended, adding, "And it's going to be a ... problem here in California."

California became a "sanctuary state" earlier this month, after Gov. Jerry Brown signed a bill that prevents law enforcement officers from "asking about immigration status during routine interactions," defying the Trump administration.

During his speech, Bannon touted "economic nationalism," contending that people who "are working two jobs" are the ones who "got screwed" while those profiting in Silicon Valley "think they get a special deal" by getting "all the benefits of a free society," according to the San Francisco Chronicle.

He blamed China for gaming the system in favor of "Silicon Valley, Wall Street, Hollywood and Washington, D.C."

Bannon, who is back at Breitbart News as executive chairman, also condemned former President George W. Bush, who just one day prior delivered speech widely seen as an implicit rebuke of Trump.

"There has not been a more destructive presidency than George Bush's," Bannon said.