TOKYO (AP) — Japan and the United States on Wednesday signed an arrangement to jointly develop a new type of missile defense system as the allies seek to defend against the growing threat of hypersonic weapons, which are possessed by China and Russia and being tested by North Korea.

The project was initially agreed between Japan’s Prime Minister Fumio Kishida and U.S. President Joe Biden at their summit in Washington last August. The Glide Sphere Interceptor is planned for deployment by the mid-2030s.

Wednesday’s agreement determines the allocation of responsibility and decision-making process, a first major step in the project, Japanese defense ministry officials said. They hope to decide on Japanese contractors and start the development process by March 2025.

Hypersonic weapons are designed to exceed Mach 5, or five times the speed of sound, posing a threat to regional missile-defense systems with their speed and maneuverability. Developing interceptors of them is a challenge.