An Airbus operated by Lufthansa's Germanwings budget airline crashed in southern France on Tuesday and all 148 on board were feared dead.
French President Francois Hollande said he believed none of those on board had survived.
"There were 148 people on board," Hollande said. "The conditions of the accident, which have not yet been clarified, lead us to think there are no survivors."
He said there was likely to be a significant number of Germans on the flight from Barcelona to Duesseldorf.
He added: "The accident happened in a zone that is particularly hard to access."
A spokesman for France's DGAC aviation authority said the airliner crashed near the town of Barcelonnette about 100 km (65 miles) north of the French Riviera city of Nice. A statement from the prime minister's office said the crash happened in Meolans-Revel, a remote and sparsely inhabited commune in the foothills of the French Alps.
Airbus said it was aware of reports about the crash.
"We are aware of the media reports," Airbus said on Twitter. "All efforts are now going towards assessing the situation. We will provide further information as soon as available."
The crashed A320 is 24 years old and has been with the parent Lufthansa group since 1991, according to online database airfleets.net