UK Prime Minister Rishi Sunak has launched the first major phase of a collaborative program between Italy, Japan, and the UK that will develop the next generation of fighter jets for the three nations. Known as the Global Combat Air Programme (GCAP), the project builds on the development work already performed by the Anglo-Italian Team Tempest, and Japan’s F-X program.

“The security of the United Kingdom, both today and for future generations, will always be of paramount importance to this government," said Sunak. “That’s why we need to stay at the cutting-edge of advancements in defense technology—outpacing and out-maneuvering those who seek to do us harm. The international partnership we have announced today with Italy and Japan aims to do just that, underlining that the security of the Euro-Atlantic and Indo-Pacific regions are indivisible.”

GCAP is a logical extension of the growing industrial cooperation with Japan by UK and Italian companies, a trend underlined during the Farnborough air show in July. The UK core of Team Tempest—comprising BAE Systems, Rolls-Royce, MBDA and Leonardo UK—has struck collaborative agreements with a number of Japanese companies, including IHI (engines), Mitsubishi Heavy Industries (aircraft technology) and Mitsubishi Electric (radar, electronic warfare).

The development phase of GCAP is due to begin in 2025, and work is now under way to establish the core platform concept and structure. Cost-sharing agreements will be set, based on a joint assessment of costs and the expected national budgets assigned to the program. Team Tempest announced at Farnborough that a technology demonstrator would fly “within five years.” As well as developing a core fighter, GCAP will also assess the needs for uncrewed air vehicles and new weapons as part of a wider future combat air system. The fighter is slated to enter service in 2035.

In a joint statement with the Japanese defense ministry, the U.S. Department of Defense signaled its approval of the GCAP, stating support for “Japan’s security and defense cooperation with like-minded allies and partners, including with the United Kingdom and Italy—two close partners of both our countries—on the development of its next fighter aircraft.” The statement also noted growing U.S. cooperation with Japan in several areas, notably on autonomous systems that could complement Japan’s new fighter.

While GCAP is being launched as a trinational program, the door remains open for other potential like-minded nations to join.