The US and Japan will allocate more than $3 billion to jointly develop a new type of missile capable of intercepting hypersonic weapons, Kyodo News has quoted an unnamed Pentagon source as saying.
The Glide Phase Interceptor (GPI) project is expected to be completed by the 2030s, and Japan is expected to commit $1 billion to the project. The program was agreed upon by US President Joe Biden and Japanese Prime Minister Fumio Kishida in August 2023.
The new missile will be designed to shoot down incoming hypersonic missiles during their most vulnerable glide phase of flight before re-entering the atmosphere from space.
The Pentagon has previously said that in Japan, the GPI is likely to be installed on "the future ASEVs - Aegis System Equipped Vessels - of the Japan Maritime Self-Defense Force". Aegis is a US system designed to defend against short- and medium-range ballistic missiles.
"The development of a counter-hypersonic capability is a pressing need for both countries to address challenges in the Indo-Pacific region, including the emergence of offensive hypersonic and other sophisticated missile capabilities for potential acts of coercion," the Pentagon added.
The GPI project comes as the US lags behind Russia and China in terms of developing hypersonic weapons, which include vehicles and missiles that travel faster than Mach 5, or five times the speed of sound.
After the US began developing a series of new anti-ballistic missile interceptors following the termination of the ABM Treaty in 2002, Russia dusted off 1980s-era plans for hypersonic weapons designed to defeat traditional ballistic missile defense systems.
China has also pioneered the development of several types of hypersonic weapons in line with its focus on long-range missiles as an asymmetric counter to the superior technology of the US military.
The Anti-Ballistic Missile Treaty, signed by the US and the then-Soviet Union in 1972, collapsed in June 2002 when America unilaterally withdrew from the agreement.