BERLIN (Reuters) - France has threatened to cancel a Franco-German project to develop a next-generation fighter jet unless Germany agrees to allow unlimited exports of the warplanes, even to countries involved in conflicts, Der Spiegel magazine reported on Friday.

The German magazine, citing a confidential cable sent by the German ambassador in France, said French officials made their position clear during a meeting in Paris on Sept. 21.

Official could not be reached for comment at the German Defence Ministry, which is overseeing the project, nor were any available at France’s Defence Ministry and the French presidency.

The project was first announced by German Chancellor Angela Merkel and French President Emmanuel Macron in July 2017, along with plans to develop a new tank.

During the September meeting, Claire Landais, France’s general secretary for defense and national security, said unlimited exports were “a central part of the financing of the overall project” and France viewed “long-term guarantees for future exports of the equipment as essential,” Spiegel said.

“Only when such guarantees have been made can the political green light be given for billions of euros in investments”, the notes quoted Landais as saying.

Last week, Airbus defense chief Dirk Hoke warned France against demanding too big of a share of the program, saying it could doom its chances for approval by the German parliament.

Airbus had agreed to let its rival, France's Dassault Aviation AVMD.PA, take the lead on developing a new combat aircraft, but that did not mean France would run the overall project, which will also include unmanned aircraft and other weapons, Hoke told French website La Tribune.

Dassault Aviation and Airbus, the respective industrial partners for France and Germany, could not immediately be reached for comment.

The Spiegel report and Hoke’s comments laid bare continued tensions over the ambitious undertaking by two countries with very different views on arms exports.

German Chancellor Angela Merkel’s government has halted arms deliveries to Saudi Arabia in protest over the murder of Saudi journalist Jamal Khashoggi inside the Saudi consulate in Istanbul on Oct. 2, a killing she has called a “monstrosity”.

France’s reaction to the Khashoggi case has been guarded to date as Paris tries to retain its sway with Riyadh and protect commercial relations spanning energy, finance and weaponry.

French President Emmanuel Macron said on Friday that calls by several EU countries including Germany to suspend arms sales to Saudi Arabia since Khashoggi’s killing smacked of populist “demagoguery”.

Airbus Chief Executive Tom Enders was critical of Germany’s stance in remarks to Der Spiegel. “Berlin cannot constantly call for European cooperation, but then back out when it gets to be concrete,” he said.

Germany, he added, was signaling to Paris that it did not consider French foreign and security policy to be responsible.