Defense Minister Itsunori Onodera on Tuesday urged the head of the U.S. Pacific Command to guarantee the safety of aircraft operating in Okinawa following two emergency landings involving U.S. military helicopters in recent days.

During his visit to Hawaii, Onodera called on Adm. Harry Harris to take thorough measures to prevent similar incidents and ensure the safety of local residents, according to Japanese government officials.

Harris expressed regret over the incidents while adding that the U.S. military makes safety a top priority in its fleet of aircraft.