The government will use Osprey tilt-rotor aircraft to conduct rescues of Japanese citizens abroad and other special operations by the Self-Defense Forces, government sources said Saturday.

Under controversial security legislation that came effect in 2016, the SDF can play an expanded role overseas.

The Ground Self-Defense Force has a special anti-terror unit to carry out rescue operations and other risky missions. But the unit is still not fully capable and lacks specialized aircraft.

The government is now set to introduce the CV-22 Osprey, the special operation forces variant of the U.S. Marine Corps MV-22 Osprey, while also considering deploying refurbished models of the GSDF's UH-60 helicopter, the sources said.

The CV-22 is widely seen as more capable of nighttime flying and its terrain-following radar enables it to fly at low altitudes, they said. The remodeled UH-60 is regarded as more bulletproof and can be carried by the Air Self-Defense Force's C-2 transport airplanes.

Japan has been seeking to enhance its capability to rescue Japanese citizen overseas since the 2013 hostage crisis in Algeria, in which 10 Japanese were killed.

The GSDF is also eyeing the use of special aircraft in the event that Japan's remote islands are occupied by foreign forces, according to the sources.

At U.S. Marine Corps Air Station Futenma in Okinawa Prefecture, 24 MV-22s have been deployed since 2012.

The Defense Ministry is considering introducing some CV-22s among 17 Ospreys it plans to deploy at Saga airport in southwestern Japan, according to the sources.

The ministry was supposed to deploy the aircraft over four years from fiscal 2018, but it has postponed delivery of the first batch of five plane from the United States, apparently because the government has struggled to win local consent because of concerns over the Osprey's safety record.

The new security laws loosened the constraints of Japan's postwar pacifist Constitution on military activity. They have allowed SDF participation in foreign peacekeeping operations, even if they are not under the control of the United Nations, at the request of international organizations.

Rescue operations in other countries might not only put SDF members' lives at risk but also create situations in which they are forced to fire back at armed groups. The Constitution bans use of force abroad.