Spain is joining France and Germany to build a next-generation fighter that could outclass the F-35

• Germany and France will welcome Spain as a full partner in their program to develop a next-generation air combat system.
• In July 2017, France and Germany announced that they would join forces to build an advanced "European" fighter to replace Dassault's Rafales and Germany's Eurofighter Typhoons. 
• Unlike the F-35, Dassault's next-generation fighter is likely to have two engines and therefore much more thrust, one analyst previously told Business Insider.

Germany and France will welcome Spain as a full partner in their program to develop a next-generation air combat system, and expect to sign an agreement finalizing the move at the Paris Air Show in June, a German government source said on Wednesday.

Paris and Berlin initially planned to offer Spain observer status on the program, but Spain this week formally asked to participate as a fully fledged partner, which will also require certain financial outlays.

"The current intention is to sign a tri-national memorandum of understanding on the sidelines of the 2019 Paris Air Show in Le Bourget," the source said.

In July 2017, France and Germany announced that they would join forces to build an advanced "European" fighter to replace Dassault's Rafales and Germany's Eurofighter Typhoons. 

In July 2018, the French aircraft manufacturer Dassault Aviation published a video giving a glimpse into what the  aircraft might look like.

"I think if they can pull it all off, this seems a legitimate candidate for a highly capable competitor to the F-35 and Su-57," Sim Tack, the chief military analyst at Force Analysis and a global fellow at Stratfor, previously told Business Insider. 

Unlike the F-35, Dassault's next-generation fighter is likely to have two engines and therefore much more thrust, Tack said.

"In terms of capabilities, the focus will probably be on stealth technology, and integration with information systems," Tack said, such as "sharing information between aircraft, possibly commanding drones, etc."

Tack added that it was up for debate whether this aircraft would be a fifth- or sixth-generation fighter.