TOKYO — A United States Navy sailor and a Japanese woman have been found dead on the Japanese island of Okinawa in what the police are investigating as a murder-suicide.

The Japanese Foreign Ministry said in a statement that the sailor, Gabriel A. Olivero of North Carolina, appeared to have fatally stabbed the woman and then killed himself with the same knife.

Mr. Olivero, 32, and the woman, 44, were found by the Okinawa police on Saturday in an apartment in Chatan, a village on the island’s southwestern coast, according to NHK, the public broadcaster, and the local news media. They have not been publicly identified.

About 25,000 American troops are stationed on Okinawa, half of all American soldiers based in Japan. Violence committed by American service members or related personnel on the island has long caused friction between Washington and Tokyo.