Maritime autonomous systems have been identified as an initial field Japan could collaborate in with the United States, Britain and Australia under their AUKUS security pact as the U.S.-led grouping also launches talks with Canada, New Zealand and South Korea to join its advanced capabilities program, known as Pillar II.

After singling out Tokyo in April as a potential candidate for Pillar II projects, AUKUS leaders said in a joint statement Wednesday that the two sides are “exploring opportunities to improve interoperability of their maritime autonomous systems as an initial area of cooperation.”

The move follows consultations earlier this year, and the emphasis on collaboration plans with Japan suggests those may be advancing faster than tie-ups with the other potential partners.