Okinawa on Saturday marked the 73rd anniversary of the end of a World War II ground battle that claimed over 200,000 lives, while Gov. Takeshi Onaga renewed calls to reduce U.S. forces in the prefecture, citing easing tensions with North Korea after the historic Singapore summit.

"Developments toward detente have begun," Onaga said in his peace declaration during the annual Battle of Okinawa memorial, adding that an ongoing plan to relocate a key U.S. base in the prefecture despite residential opposition "goes against the trend."

Prime Minister Shinzo Abe, who also attended the ceremony, said the government will stick to the relocation plan for U.S. Marine Corps Air Station Futenma, which sits in a residential part of Ginowan.