Japan on Tuesday released its annual Defense of Japan report, expressing concern over Chinese naval vessels' activities in the Pacific Ocean.

The report noted that China is likely to expand its sphere of maritime activities, and conduct operations and training as routine practices in waters near Japan including the East China Sea, the Pacific Ocean, and the South China Sea, which Tokyo is increasingly worried about.

On Democratic People's Republic of Korea (DPRK), the paper warned of continued missile tests following a failed launch in April that the DPRK said was a satellite launch but was viewed by many other countries as a ballistic missile test.

The paper also discusses Japan's bilateral security alliance with the United States. But it says only a little about the planned U.S. deployment of MV-22 Osprey transport aircraft at the U.S. Futenma Air Station in Ginowan, Okinawa Prefecture, without detailing plans on how to ease safety concerns about the aircraft.

Japan releases the defense white paper annually to state its view of the surrounding security environment and its defense policy.