"The French need, in the next generation of fighter jets, an aircraft capable of carrying nuclear weapons and operating from an aircraft carrier. That's not what we currently need in the German military," Merz said on the German podcast Machtwechsel.

The Future Combat Aircraft System (FCAS) programme was launched in 2017 to replace France's Rafale jet and the Eurofighter planes used by Germany and Spain by 2040.

But the scheme, jointly developed by the three countries, stalled last year as France's Dassault Aviation got into heated disputes with Airbus, which represents German and Spanish interests in the project.

The project has also fallen foul of wider Franco-German disagreements, with Berlin accusing Paris of not making enough effort to boost defence spending.

Merz had previously pledged a decision on FCAS by the end of last year but has postponed making the final call.

France has continued to insist the project is viable.

Merz said on the podcast that France and Germany were now "at odds over the specifications and profiles" of the kind of aircraft they needed.

"The question now is: do we have the strength and the will to build two aircraft for these two different requirement profiles, or only one?" he asked.

If this issue is not resolved, he said Germany would "not be able to continue the project", adding that there were "other countries in Europe" ready to work with Berlin.

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Dassault Aviation

Airbus Group