The US Defense Security Cooperation Agency has notified Congress of the potential $821m foreign military sale (FMS) of Standard Missile-2 (SM-2) Block IIIB, equipment and support to Japan.

Under the FMS, Japan has requested for up to 246 SM-2, Block IIIB vertical launching tactical all-up rounds, RIM-66M-09.

Approved by the US State Department, the potential sale also covers MK 13 MOD 0 vertical launching system canisters, operator manuals and technical documentation, US Government and contractor engineering, technical and logistics support services.

"Japan has already installed SM-2 Block IIIA/IIIB missiles on its four Kongo-class and two Atago-class destroyers."

Raytheon and BAE Systems will serve as the principal contractors for the sale.

The SM-2 Block IIIB missiles will be fitted on Japan’s two new Aegis-equipped destroyers, which are being built based on a modified Atago-class hull.

The missiles can be combined with the Aegis combat system to boost Japan’s area defence capabilities over critical east Asian and western Pacific air and sea-lines of communication.

Japan has already installed SM-2 Block IIIA/IIIB missiles on its four Kongo-class and two Atago-class destroyers, and has two intermediate-level maintenance facilities that can maintain the SM-2 Block IIIB missiles.

The Raytheon-built SM-2 Block IIIB missile is a fleet-area air defence weapon designed to provide protection against anti-ship missiles and enemy aircraft.

The missile features advanced semi-active radar seeker technologies, tail controls and solid rocket motor propulsion, an active radar target detection device and a directional warhead.

The missile system is currently deployed on-board the US Navy's Ticonderoga-class cruisers and Arleigh Burke-class destroyers, and is launched from the MK 41 vertical launcher system (VLS).

Image: Launch of RIM 66M missile from Spanish frigate Canarias. Photo: courtesy of Mass Communication Specialist 2nd Class Johansen Laurel.