Korea and the United States have seen problems in coordination in recent military activities. The latest issue involved a U.S. Forces Korea (USFK) drill conducted over the West Sea without detailed prior coordination with Korea’s military. According to military sources, the United States on Jan. 15 proposed a trilateral air exercise with Korea and Japan. The proposed timing overlapped with the Lunar New Year holiday period and came shortly before Japan’s “Takeshima Day,” in which Japan renews its claim over Korea's easternmost Dokdo islets. This timing prompted Seoul to request adjustments. Korea suggested either bringing the exercise forward to distance it from the date or holding a Korea-U.S. bilateral drill afterward. Washington later informed Seoul on Feb. 5 that it would proceed with a U.S.-only exercise, the sources said. But the U.S. conducted joint air drills with Japan on Feb. 16 and 18 over the East Sea and the East China Sea. The exercises involved four B-52 strategic bombers and Japanese fighter aircraft. USFK also carried out a solo drill over waters west of the Korea