British Prime Minister Keir Starmer will meet his Japanese counterpart Sanae Takaichi on Sunday as uncertainty mounts over their joint fighter jet program with Italy because of doubts about the U.K.¡¯s commitment.

The Global Combat Air Program ¡ª an initiative between the three nations to develop a next-generation fighter jet by 2035 ¡ª has faced roadblocks including delays to Britain¡¯s financial contribution to the project.

Britain had been expected to unveil billions of pounds for the GCAP in late 2025 as part of its 10-year defense investment plan, but it was postponed by several months due to a spending row between the U.K. defense ministry and Treasury.