TAIPEI—A U.S. aircraft carrier group led by the USS Ronald Reagan has entered the South China Sea as part of a routine mission, the U.S. Navy said on Tuesday, at a time of rising tensions between Washington and Beijing, which claims most the disputed waterway. China frequently objects to U.S. military missions in the South China Sea, and the announcement follows China blasting the Group of Seven nations for a statement scolding Beijing over a range of issues. “While in the South China Sea, the strike group is conducting maritime security operations, which include flight operations with fixed and rotary-wing aircraft, maritime strike exercises, and coordinated tactical training between surface and air units,” the U.S. Navy said. “Carrier operations in the South China Sea are part of the U.S. Navy’s routine presence in the Indo-Pacific.” The carrier is being accompanied by the guided-missile cruiser USS Shiloh and the guided-missile destroyer …