The US Air Force, which was operating the tilt-rotor aircraft, says the cause of the mishap, which killed at least one person, is currently unknown.Â
The condition of the other seven people on board is not known.
"The occurrence of such an accident causes great anxiety to the people of the region... and we are requesting the US side to conduct flights of Ospreys deployed in Japan after these flights are confirmed to be safe," Minoru Kihara said in parliament on Thursday, reversing a decision on Wednesday to allow such flights to continue.
The Japan Self-Defense Forces (SDF), which also operates Ospreys, will suspend flights of the transport aircraft until the circumstances of the incident are clarified, another senior defence ministry official said in parliament.
A spokesperson for US military forces in Japan did not immediately respond to a request for comment.
Witnesses said the aircraft's left engine appeared to be on fire on Wednesday afternoon as it approached an airport for an emergency landing in clear weather and light winds, media reported.
The Osprey V-22 is operated by the US Air Force, Marines and Navy, and Japan's armed forces. (AP PHOTO)
Developed by Boeing and Bell Helicopter, the hybrid V-22, which can land and take off like a helicopter and fly like a fixed-wing aircraft, is operated by the US Air Force, Marines and Navy, and the SDF.
The deployment of the aircraft in Japan has been controversial, with critics of the US military presence in the southwest islands saying it is prone to accidents. The US and Japan say it is safe.
Japan hosts the biggest overseas concentration of US military power, with the country home to the only forward-deployed US carrier strike group, its Asian airlift hub, fighter squadrons and a US Marine Corps expeditionary force.
In August, a US Osprey crashed off the coast of northern Australia while transporting troops during a routine military exercise, killing three US Marines.
Another crash-landed in the ocean off the southern island of Okinawa in December 2016, the first such incident in Japan, prompting a temporary US military grounding of the aircraft.
The last fatal US military aircraft crash in Japan was 2018, when a mid-air collision during a training exercise killed six people, according to the defence ministry.
