China claims most of the energy-rich South China Sea through which about $5 trillion in ship-borne trade passes every year. US commanders said that yesterday a Chinese observation ship closely followed the USS John C Stennis carrier the moment it entered the disputed East China Sea region , again heightening tensions in the area ; the American carrier was joining warships from Japan and India for drills near the area . Japan also said yesterday that a separate Chinese navy observation ship entered its territorial waters south of its southern Kyushu island . China has become increasingly angered by what it sees as provocative US military patrols near the disputed waters , however , the US argue the patrols are to protect freedom of navigation .
US commanders said that yesterday a Chinese observation ship closely followed the USS John C Stennis carrier the moment it entered the disputed East China Sea region , again heightening tensions in the area ; the American carrier was joining warships from Japan and India for drills near the area . Japan also said yesterday that a separate Chinese navy observation ship entered its territorial waters south of its southern Kyushu island . China has become increasingly angered by what it sees as provocative US military patrols near the disputed waters , however , the US argue the patrols are to protect freedom of navigation .