Uber is temporarily halting self-driving car tests in all locations after a deadly accident, in what is likely the first pedestrian fatality caused by a self-driving car.

Programs in San Francisco, Pittsburgh, Phoenix and Toronto will be paused after a woman was hit and killed overnight by an Uber self-driving car when walking across a street in Tempe, Arizona.

The Governors Highway Safety Association estimates that there were about 5,984 pedestrian fatalities in 2017, and none have been publicly linked to an autonomous vehicle, but crash-reporting standards for incidents involving autonomous vehicles are still evolving.

There was a vehicle operator in the car but no passengers at the time of the accident, according to Tempe police, which responded to the scene at around 10 p.m. on Sunday. The 49-year-old victim died after being transported to a local hospital, police said.

"Our hearts go out to the victim's family. We are fully cooperating with local authorities in their investigation of this incident," Uber said in a statement.

Tweet: Some incredibly sad news out of Arizona. We're thinking of the victim's family as we work with local law enforcement to understand what happened.

A spokesman for the National Transportation Safety Board told CNBC it is investigating the accident. The Arizona governor's office said it is talking with law enforcement. The National Highway Traffic Safety Administration is also investigating the incident.

A year ago, Uber suspended the same program after a different Arizona crash which did not result in any serious injuries.

The NTSB has already scrutinized accidents involving Tesla's autopilot technology, but those cars operate with different technology than what Uber was testing.

Uber's self-driving car business has already seen setbacks after it was embroiled in a lawsuit with Alphabet's Waymo for much of the past year. That case was recently settled under Uber's new leadership.

— CNBC's Robert Ferris, Leslie Josephs and Jim Forkin contributed to this report.