The company said it delivered 499,550 vehicles last year which was above Wall Street estimates, but was 450 units shy of Musk's target.

Nonetheless, Musk on Saturday tweeted: "So proud of the Tesla team for achieving this major milestone! At the start of Tesla, I thought we had (optimistically) a 10% chance of surviving at all."

Congratulations poured in on Twitter after Tesla defied the larger auto industry trends of slumping sales, quarterly losses and global supply chain disruptions.

Tesla's share price has risen more than 700% over the last year, but some investors criticized Tesla for saying at the start of 2020 that it would "comfortably exceed 500,000 units" for the year.

Looking forward, Tesla has pinned hopes on new markets such as Europe and Asia, with competition intensifying in the U.S., as automakers double down on their investments in the electric vehicle sector.