BERLIN (Reuters) - The German military needs a “fifth-generation” replacement for its Tornado fighter jets that is hard to detect on enemy radars and can strike targets from a great distance, the chief of staff of the air force said on Wednesday.

Lieutenant General Karl Muellner’s comments are his clearest public statements to date on the Tornado replacement program. They indicate a preference for Lockheed Martin Corp’s F-35 fighter jet, the only Western aircraft that meets those requirements.

The air force last month issued a formal request for information about the F-35, as well as three other jets: the F-15 and F/A-18E/F, both built by Boeing Co, and the European Eurofighter Typhoon.

Germany is kicking off the process of replacing its 85 Tornado jets, which will go out of service around 2030.

The program could be worth billions of euros for the winning bidder in coming years.

Muellner told Reuters Germany would need to buy an off-the-shelf replacement that could enter service around 2025 to facilitate a smooth transition with the Tornado, noting that did not leave enough time to develop a unique solution.

But he said changing warfare requirements and the need for a credible deterrent meant the successor fighter had to be “low-observable, and able to identify and strike targets from a great distance”.

“It will have to be a fifth-generation jet to meet the full spectrum of our needs,” Muellner said.

Many German allies in Europe, including Norway, the Netherlands, Britain, Italy, Turkey and Denmark have selected the F-35 and some have received initial deliveries. Belgium is expected to make a decision next year.

Lockheed is rolling out the red carpet, bringing its F-35 flight simulator to Berlin and offering members of parliament, ministry and military officials and a journalists a chance to “fly” the stealthy single-seat, single-engine fighter.

It even printed a new version of its standard F-35 lapel pin in the black, red and gold colors of Germany’s flag.

Any new fighter jet purchase would have to be approved by parliament in the next two years and a contract signed by 2020 or 2021 to ensure deliveries by 2025.

A purchase of around 100 jets would help ensure German industry got a decent share of work on the program.

Steve Over, Lockheed’s director of F-35 international business development, welcomed the comments and said Lockheed stood ready to support the German government in its selection process. He said most F-35 foreign military sales involved some work for companies in the buying country.

Over told Reuters the price of the aircraft would have dropped to around $80 million by the time Germany would need to sign a contract. He said interest was growing in the F-35 given the changing threat environment.

“It’s really about giving nations a deterrent capability. Because if you’re got the capability to take an airplane into another country’s airspace and they don’t even know you’re there, that’s an incredible deterrent,” he said.

Muellner said he also strongly supported a Franco-German plan to develop a successor for its fleet of what will be 140 Eurofighter Typhoon jets, built by Britain’s BAE Systems Plc, Italy’s Leonardo and Airbus.

The project, unveiled in July, would help preserve critical technology skills in Europe and allow Europe to develop its own low-observable technology, Muellner said.

Airbus last week said that choosing an interim U.S. fighter that could eventually become a longer term commitment might interfere with the Franco-German fighter.

Industry sources said a decision to order the F-35 would be negative for Airbus, which is part of the Eurofighter consortium and is seen as one of the key partners in the Franco-German initiative announced earlier this year.

Muellner said the German air force had also committed to NATO to provide a fleet of 14 electronic warfare aircraft by the middle of the next decade, which meant it would likely have to buy around 20 such jets.

Possible candidates could be the Boeing EA-18 Growler, a modified A400M transport plane that could provide stand-off jamming capability, or a modified Eurofighter, experts said.

No decisions on that program have been made.