A former highways agency chief who served under president Barack Obama says it is inevitable that driverless cars will kill people as they appear on the road.
Mark Rosekind, the former United States highway traffic safety administrator, warned "there will be some lives lost" as tech companies and car manufacturers experiment with autonomous vehicles, but he insisted they will eventually lead to much safer streets, according to the Daily Telegraph.
Discussing the future of transport on BBC Radio 4, he said: "Unfortunately, there will be crashes. People are going to get hurt and there will be some lives lost."
Despite this, he said, both businesses and regulators "should really be focused on the potential for zero deaths on our roadways".
The technology industry is locked in a debate surrounding the ethics of releasing autonomous systems "into the wild", after investments from Google, Uber, Tesla and carmakers significantly accelerated their development.
Rosekind's comments mark a rare admission from an official acknowledging the trade-off for loss of life now in order to achieve safer roads tomorrow.
Rosekind now serves as head of safety innovation at driverless car start-up Zoox.
His comments follow Tesla billionaire Elon Musk's criticism of journalists who have been reporting on a series of Tesla Autopilot crashes.
Tesla stock has slumped after a series of negative headlines surrounding fatal crashes involving Autopilot functions and delays to its new Model 3 electric car, prompting Musk to hit out at the "holier-than-thou hypocrisy of big media companies who lay claim to the truth, but publish only enough to sugarcoat the lie".
Musk, stoked by the media's preoccupation with his cars, even promised a new business venture: a website that allows users to rank news organisations' credibility.
Concerns over Tesla's Autopilot system, which takes some control over cars driving on motorways, were raised in March when a Model X was involved in a fatal crash in California.
Earlier that month, Elaine Herzberg, 49, was killed crossing the road by one of Uber's driverless cars.
The ride-sharing app said it would pause the trials that it was undertaking in five US states.
Musk has repeatedly claimed that the chances of a road accident are less with Autopilot, so long as the driver keeps their hands on the steering wheel.
"It's important to emphasise we'll never be perfect," he recently told US broadcaster CBS.
"Nothing in the real world is perfect. But I do think that long term, it can reduce accidents by a factor of 10. So there are 10 fewer fatalities and tragedies and serious injuries. And that's a really huge difference."
He hit out at The Wall Street Journal after it published a report on the amount of Tesla recalls, pointing out that "there were dozens of recalls by other car companies last month, including with injuries and deaths, but you only wrote an article about Tesla".
The billionaire's outbursts have also seen him accusing analysts on earnings calls of asking "boring, bonehead questions".