More than two dozen aircraft from the U.S., Japan and U.K. conducted tactical air exercises Thursday over waters east of Okinawa, Japan, as the security environment in the region grows “increasingly severe,” military officials said. The Japan Air Self-Defense Force (JASDF) fielded two F-15 Eagle fighters. The tactical air exercise, Japan said, demonstrated the U.K. commitment to contributing to peace in the Indo-Pacific and confirmed the close coordination among the Japanese, U.S. and U.K. militaries. Over the past two weeks, the U.K. CSG has conducted tactical training with Japan’s air defense force in the Sea off Japan. On Sept. 6, the JASDF deployed four F-35A and eight F-15 fighters to drill with four F-35B fighters from Prince of Wales, Japan officials said in a Sept. 8 news release.