U.S. President Donald Trump said on Friday that billionaire Elon Musk will remain a close adviser, after the Tesla CEO ended a chaotic four-month stint leading the administration's sweeping cost-cutting campaign.

Tesla CEO Elon Musk's role with the Trump administration ended on Wednesday and will be able to focus more time on Tesla, as the company has faced headwinds this year.

Tesla investors sent a letter to the company's board chair demanding Elon Musk returns to work as tech billionaire steps away from Washington.

Elon Musk's break with the Trump administration means investors will hope he refocuses on his sprawling empire as Tesla battles slumping sales and after SpaceX's latest rocket launch fell short of expectations.

Elon Musk may have stepped away from his duties as the lead of the Department of Government Efficiency and adviser to President Trump, but he’s still active in D.C. circles. This time, he’s on the other side, lobbying lawmakers on legislation related to autonomous vehicles, according to a report by Bloomberg that cited unnamed sources.

Tesla shares slid Friday, but posted gains for the week and second straight month as CEO Elon Musk steps back from his role leading the cost-cutting Department of Government Efficiency.

Trump marked the end of Musk's tenure as a government employee with an Oval Office event. Musk arrived with a literal and reputational black eye.