The U.S. Navy will replace the V-22 Osprey tilt-rotor transport aircraft in Japan with a newer variant, possibly starting in 2021, according to a U.S. military official.

CMV-22Bs will replace the two aging C-2 Greyhounds attached to the U.S. aircraft carrier Ronald Reagan based at the U.S. Navy's Yokosuka base in Kanagawa Prefecture starting in 2021, or as late as 2026, the official said Monday.

The navy does not have a specific timeline to replace the C-2 aircraft, but it expects the last one to retire in 2026, the official said.

At present, the two C-2 Greyhounds are based at Naval Air Facility Atsugi outside Tokyo. But the CMV-22Bs are likely to be stationed at the U.S. Marine Corps' air base in Iwakuni, Yamaguchi Prefecture.

The Japanese and U.S. governments have agreed to transfer the C-2 Greyhounds and other carrier-based aircraft to Iwakuni as part of efforts to reduce noise for residents near the Atsugi base.

In the event the nuclear-powered Ronald Reagan operates in the East and South China seas, the CMV-22Bs are likely to move to the carrier from the Iwakuni base to perform such roles as transporting personnel, goods and materials.

The U.S. military has deployed MV-22 Osprey aircraft to the U.S. Marine Corps' Air Station Futenma in Ginowan, Okinawa Prefecture. It plans to locate the CV-22, the air force variant of the MV-22, at Yokota Air Base in western Tokyo in 2017.

The U.S. military maintains that the Ospreys are safe, but a series of crashes have sparked concern in Japan about their reliability.