Five Osprey tilt-rotor aircraft were formally deployed Monday at the U.S. military's Yokota Air Base in western Tokyo, despite opposition and safety worries among local residents.

The Defense Ministry hopes the deployment of the CV-22 Ospreys will enable timely responses to various contingencies in the face of China's maritime assertiveness and uncertainty over the situation on the Korean Peninsula.

It is the first deployment of Ospreys outside Okinawa, where a total of 24 MV-22 Ospreys, another U.S. Marine Corps variant, are based. Okinawa is home to the bulk of U.S. military facilities in Japan.