Japan says military tensions over Taiwan - and the economic and technological rivalry between the United States and China - threaten peace and stability in East Asia.
Japan's Ministry of Defense took up the issue of the stability of Taiwan in its time in its annual defense white paper. Japan said stabilizing the Taiwan situation was important for Japan's security and the stability of the international community.
The report goes beyond the 2020 defense white paper which said "attention needs to be paid to trends" regarding Taiwan and China forces.
China rejected Japan's conclusions about normal military activity - calling them irresponsible, according to Reuters.
"This is very wrong and irresponsible. China expresses strong dissatisfaction and firm opposition to this," the Global Times quoted China foreign ministry representative Zhao Lijian as saying.
The increase in recent China military activity around Taiwan has Japan worried because Taiwan is close to the Okinawa chain at the western end of Japan's archipelago.
According to the defense report, Japan is lagging further behind China in terms of military capability.
China has 1,146 fourth- and fifth-generation warplanes compared with Japan's 313. China has 71 modern navy destroyers and frigates compared with Japan's 47 and 52 modern submarines compared with Japan's 21, reports said.
China claims Taiwan as its territory and won't rule out the use of military force to retake the island.
Zhao said China would never let any nation intervene in the Taiwan question in any way. "China must and will reunify," he told Global Times.
Japan has become more vocal with Japan Deputy Prime Minister Taro Aso saying earlier this month that Japan should join forces with the U.S. to defend Taiwan from any invasion.
