The crash happened late Saturday in northern Niger, where French forces operating under the anti-jihadist Operation Barkhane are deployed.

An American soldier was in the car and a US defense official said both the French and US militaries are probing the incident.

The official could not speak for the French investigation, but said the US probe would look at who was driving and if they had been under the influence of alcohol.

"We are investigating all circumstances," the official said.

In a statement, US Africa Command said the "accident was not related to combat or to any active operations."

The US service member, assigned to US Special Operations Command, was medically evacuated to Europe for treatment.

Citing anonymous Pentagon officials, the New York Times on Tuesday reported the American is a Green Beret and he had been behind the wheel.

France's 4,500-member Barkhane anti-terror force in West and Central Africa has intervened mainly in Mali, while focusing on training in Burkina Faso and the other nations of the G5 Sahel military alliance -- Chad, Mauritania and Niger.

But in recent weeks operations have also extended to Burkina Faso.

US troops work across Africa with partner militaries to provide training, intel sharing and support.

The Pentagon last month announced it would trim about 10 percent of the 7,200 US troops in Africa as part of a broader shift in focus towards "Great Power" competitors such as China and Russia.