Tesla reported a 13 percent drop in first-quarter auto sales Wednesday amid lower production during factory upgrades and blowback over CEO Elon Musk's work for the Trump administration.

Musk's electric vehicle company delivered 336,681 autos in the quarter ending March 31, missing analyst expectations, as it pointed to the "loss of several weeks of production" while it ramps up upgrades for its Model Y output.

Tesla shares fell more than six percent in early trading after the deliveries fell by more than expected from the year-ago stretch. Shares later partially rebounded.

The weak car sales add to questions about Musk's continued stewardship at the EV maker, which has been targeted for consumer boycotts and vandalism as the billionaire has helped engineer thousands of job cuts across the US federal government.

Wedbush's Dan Ives, a prominent technology analyst who has been a longtime believer in Tesla's growth potential, called the figures "a disaster on every metric," according to a note.

"It's a fork in the road moment," Ives said.

"The more political he gets... the more the brand suffers, there is no debate. This quarter was an example of the damage Musk is causing Tesla."

Ives, who has called for Musk to publicly outline how he is balancing his commitments as Tesla CEO with his work for Trump, said "this continues to be a moment of truth for Musk to navigate this brand tornado crisis moment and get onto the other side of this dark chapter for Tesla."