The U.S. navy says an aircraft carrying 11 crew and passengers has crashed into the Pacific Ocean while en route to the aircraft carrier USS Ronald Reagan.
The navy tweeted that eight people were found in good condition and a search continued for three others.
The Japan-based 7th Fleet says in a statement that the search and rescue operation has been launched from the carrier.
"Personnel recovery is underway and their condition will be evaluated by USS Ronald Reagan medical staff," the statement said.
It said the ship was operating in the Philippine Sea, which is east of the Philippines, when the crash occurred at 2:45 p.m. Japan time. The names of the crew and passengers are being withheld pending next of kin notification.
The cause of the crash was not immediately clear, the Navy said.
The White House said President Donald Trump has been briefed on the incident.
Trump said in a tweet: "We are monitoring the situation. Prayers for all involved."
White House spokesperson Lindsay Walters provided no additional details or comment.
Military exercises with Japan
The plane was taking part in an ongoing joint U.S.-Japan naval exercise in waters surrounding Okinawa from Nov. 16-26. The navy called it the "premier training event" between the two navies, designed to increase defensive readiness and interoperability in air and sea operations.
The 7th Fleet has had two fatal accidents in Asian waters this year, leaving 17 sailors dead and prompting the removal of eight top navy officers from their posts, including the 7th Fleet commander.
The USS John S. McCain and an oil tanker collided near Singapore in August, leaving 10 U.S. sailors dead. Seven sailors died in June when the USS Fitzgerald and a container ship collided off Japan.
The navy has concluded that the collisions were avoidable and resulted from widespread failures by the crews and commanders, who didn't quickly recognize and respond to unfolding emergencies. A navy report recommended numerous changes to address the problems, ranging from improved training to increasing sleep and stress management for sailors.