The U.S., U.K. and Australia are considering working with Japan under their AUKUS security pact, top officials from the three countries said Monday, though analysts say challenges still loom large for Tokyo.

The three countries said they were weighing inviting Tokyo to join the pact’s second program, known as Pillar II, with Britain adding that consultations with Japan and other countries as potential collaborators would begin later this year.

“Recognizing Japan's strengths and its close bilateral defense partnerships with all three countries, we are considering cooperation with Japan on AUKUS Pillar II advanced capability projects,” the defense chiefs from the three countries said in a statement.