South Korea plans to upgrade its Patriot Air and Missile Defense systems to the PAC-3 variant, American defense contractor Raytheon announced Monday.

The South Korea military awarded Raytheon a $770 million dollar contract to upgrade the country’s Patriot systems. These upgrades are intended to prepare the South for the Patriot Advanced Capability-3 (PAC-3) missile interceptor, which would serve as an improved counter against the North Korean ballistic missile threat. This purchase represents the latest move in what has developed into something of an arms race between North Korean missiles and South Korean missile interceptors.

The South Korean military currently fields