The US State Department has approved a potential sale of up to 56 Standard Missile-3 (SM-3) Block IB missiles to Japan for an estimated $1.15bn.

The required certification notifying Congress of the foreign military sale has been delivered by the Defense Security Cooperation Agency (DSCA).

Alongside SM-3 Block IB missiles, Japan also seeks to purchase missile canisters.

In addition, the deal covers technical assistance from US Government and contractor representatives, engineering and logistical support services, and other related elements of logistics and programme support.

In a statement, DSCA said: “This proposed sale will support the foreign policy and national security of the United States by improving the security of a major ally that is a force for political stability and economic progress in the Asia-Pacific region. It is vital to US national interests to assist Japan in developing and maintaining a strong and effective self-defence capability.”

Procurement of the weapons will enable Japan to enhance its ballistic missile defences.

“It is vital to US national interests to assist Japan in developing and maintaining a strong and effective self-defence capability.”

The improved capability will allow the government to defend the Japanese homeland and US personnel stationed in the country.

The DSCA noted that the missiles can be easily integrated into Japan’s armed forces.

Raytheon Missile Systems has been selected as the prime contractor to supply the SM-3 Block IB All Up Rounds. BAE Systems is the prime contractor for the canisters.

US Government and contractor representatives will make annual trips to Japan to perform technical reviews, support, and oversight for about five years.

In November last year, the US State Department cleared a possible sale of eight SM-3 Block IB and 13 SM-3 Block 2IIA missiles to Japan.

The SM-3 interceptor is used by the US Navy to destroy short to intermediate range ballistic missiles.

SM-3 Block IIA features larger rocket motors that will enable it to defend broader areas from ballistic missile threats. The interceptor also contains a larger kinetic warhead.