Billionaire Elon Musk blasted President Donald Trump's senior trade advisor Peter Navarro as "truly a moron" and "dumber than a sack of bricks" on Tuesday in a growing rift over the US tariff policy that has rocked the world.

The extraordinary public spat came after Navarro described the Tesla boss and so-called Department of Government Efficiency (DOGE) chief as "not a car manufacturer" but "a car assembler" who relies on imported parts.

Musk, the world's richest person, has previously signaled his opposition to the president's new import tariffs that have roiled markets.

"Navarro is truly a moron. What he says here is demonstrably false," Musk posted on his X social network, under a clip of Navarro saying Tesla imported batteries, electronics and tires, and that Musk "wants the........

© International Business Times