The United States will start deploying missile interceptors at a key air force base in Japan from this summer, as part of efforts with Tokyo to deal with North Korea's missile arsenal, the Japanese Foreign Ministry said on Thursday.

The U.S. military will install Patriot Advanced Capability-3 surface-to-air interceptors at its Kadena Air Base on the southern Japanese island of Okinawa from September and plans to make them partly operational by the end of the year, the ministry said.

They will be fully operational by the end of March, a ministry official added.

The deployment of the PAC-3s at Kadena - the largest U.S. air base in the Asia-Pacific would be the first at a U.S. facility in Japan.

Japanese officials said while the system was meant to protect the country from North Korea's missiles -- which include hundreds of Rodong missiles that can hit all of Japan, the timing of the deployment, soon after Pyongyang's test-firing of seven missiles earlier this month, was a coincidence.

Japan and the United States had agreed in May to deploy the PAC-3s at U.S. military facilities in Japan as soon as possible, as part of a realignment of U.S. forces in Japan.

The PAC-3s are the U.S. military's state-of-the-art missile interceptors and are designed to shoot down incoming ballistic missiles at their terminal phase, shortly before they reach their targets, by firing interceptor missiles at them.

But military analysts say the system can cover an area within a radius of up to 10 km, and Japanese officials said the PAC-3s at Kadena will only be able to cover parts of Okinawa.

Separately, Japan plans to equip its own military, the Self-Defence Forces, with PAC-3s, and is set to deploy the first such system at an air base just north of Tokyo by the end of March, officials said.

As part of U.S.-Japan cooperation on missile defence, the U.S. Navy will deploy Shiloh, a cruiser equipped with the Aegis missile tracking and engaging system, at one of its bases in Japan, the officials added.