Reuters reports the United States is damaging stability in the Asia-Pacific region by positioning a missile defense radar in Japan, China said on Thursday. Japan, an ally of the United States, has voiced growing anxiety over China's more assertive posture in the East China Sea, where the neighbors are locked in a dispute over control of a group of uninhabited islets. North Korea has carried out a series of missile tests this year, including two medium-range missiles capable of hitting Japan. Pyongyang has also threatened another nuclear test. Japan's defense ministry has said an X-Band radar system was delivered on Tuesday to the U.S. military's communication facility in Kyoto in the western part of the country. It is scheduled to be fully operational by the end of the year.