Japan's Defense Minister Kishi Nobuo has expressed concern over the activity of a Chinese aircraft carrier in waters near Japan's remote islands and Taiwan.

Kishi said on Tuesday that Chinese fighter jets and helicopters were seen taking off from and landing on the aircraft carrier Liaoning more than 100 times from May 3 to Sunday.

The defense ministry has been monitoring the vessel since it traveled south through the waters between Okinawa's main island and Miyakojima island and into the Pacific Ocean on May 2.

Kishi said the naval activity could be part of China's efforts to improve the carrier's operational capability and enhance the ability to carry out operations in more distant locations.

He said in view of the fact that the naval activity is occurring near Japan's southwestern islands and Taiwan, the government has no choice but to closely monitor the situation.