US regulators asked Tesla Wednesday to recall 158,000 cars in the United States because of a safety-related defect.

The National Highway Traffic Safety Administration said in a letter to Tesla that a problem with the cars' display screen and related failures result in loss of rearview camera and other safety-related vehicle functions.

The agency said the defect has been found in certain 2012 through 2018 Tesla Model S cars and 2016 through 2018 Model Xs.

Safety investigators have "tentatively concluded that the failure of the media control unit (MCU) constitutes a defect related to motor vehicle safety," the letter said.

In the vehicles, failed media control units can result in a car's touchscreen going blank, at which point "a rearview/backup camera image is no longer available to the driver. If this image is not available, the risk of crash increases potentially causing injury or death."

The MCU failure can also prevent use of the vehicle's windshield defogging and defrosting system, impact the autopilot system and affect the turn-signal functionality "due to the possible loss of audible chimes, driver sensing and alerts associated with these vehicle functions."

The failure rate "in this investigation is significantly greater than the failure rate for vehicles involved in prior recalls involving similar behavior," the statement read.

In the letter regulators asked Tesla to "initiate a recall to notify all owners, purchasers and dealers" about the safety defect "and provide a remedy."

Tesla, under the leadership of brash founder and CEO Elon Musk -- the world's wealthiest person -- is under no obligation to comply with the federal agency's request, but has until January 27 to provide an explanation.

The request is a major headache for the company, as 158,000 vehicles represent nearly one-third of all cars delivered by the manufacturer in 2020.

It also comes at as the price of shares in the California-based company are on the rise, fueled by the assumption that electric technology is the medium-term future of automobiles.