The joint missile development plan was agreed upon by US President Joe Biden and Japanese Prime Minister Fumio Kishida in August 2023.

On May 2, a US Department of Defense official said that the US and Japan estimate the total cost of the project to develop a new missile capable of intercepting hypersonic weapons will be over 3 billion USD.

According to sources, of the total amount spent on this project, Japan will spend 1 billion USD.

Both the US and Japan aim to complete missile development by the 2030s.

The joint missile development plan was agreed upon by US President Joe Biden and Japanese Prime Minister Fumio Kishida in August 2023.

The new missile is capable of intercepting incoming hypersonic missiles in their glide phase, compared to conventional defense systems designed to intercept missiles just before they reach their targets. This is the second time Japan and the US have jointly developed an interceptor missile after the Standard Missile-3 Block 2A.

Hypersonic missiles and glide vehicles can fly at speeds greater than Mach 5, five times the speed of sound. They are also maneuverable and can change direction during flight, making them harder to shoot down or track by radar.