Trump promised to buy a new Tesla car to show support for the electric car maker's chief and his ally Elon Musk amid recent "Tesla Takedown" protests and the slump in the company's stock price.
Shares of the automaker rose about five per cent in pre-market trading, rebounding from the biggest one-day fall in four-and-a half years.
Musk's role in sweeping cuts to the federal workforce at the behest of Trump has led to protests in the US against Tesla.
About 350 demonstrators protested outside a Tesla electric vehicle dealership in Portland, Oregon, last week, while nine people were arrested during a raucous demonstration outside a New York City Tesla dealership earlier in March.
In a post on his Truth Social platform, Trump defended Musk, saying he was "putting it on the line" to help the country and was doing a "fantastic" job.
"I'm going to buy a brand new Tesla tomorrow morning as a show of confidence and support for Elon Musk, a truly great American," Trump said.
Musk thanked the president for his support on his own social media platform X.
Trump in January took aim at electric vehicles, revoking a 2021 executive order signed by his predecessor Joe Biden that sought to ensure half of all new vehicles sold in the US by 2030 were electric.
With AAP.