Meta CEO Mark Zuckerberg expressed concerns about plans for a national AI regulator in a previously unreported phone call with President Donald Trump last month, marking the involvement of one of the world’s top tech executives in a fraught White House policy debate.

The proposal, championed by the Nobel Prize-winning Google DeepMind scientist Demis Hassabis and favored by some top White House officials, would create an independent organization modeled on the Financial Industry Regulatory Authority, or FINRA, the organization that oversees the securities industry under the supervision of the Securities and Exchange Commission. White House…