SEOUL, South Korea—The U.S. aircraft carrier Ronald Reagan concluded a naval exercise with South Korea in the Philippine Sea on Saturday, the two militaries said, amid signs that North Korea is possibly preparing to conduct its first nuclear test explosion since 2017.
The three-day exercise that began Thursday in international waters off the Japanese island of Okinawa was apparently the allies’ first joint drill involving a U.S. aircraft carrier since November 2017.
The Ronald Reagan then joined the USS Theodore Roosevelt and Nimitz in a rare three-carrier exercise with South Korean naval vessels during North Korea’s last provocative run in nuclear and intercontinental ballistic missile tests….