BEIJING, Nov. 28 -- China's Air Defense Identification Zone (ADIZ) over the East China Sea is completely justified and legitimate, Defense Ministry spokesman Yang Yujun said on Thursday.

Yang's comments were in response to a question about Japanese media reports that China had altered the status quo unilaterally by announcing the ADIZ on Saturday.

"Japan has always accused or tarnished other countries without reflecting on their own deeds," Yang said at a regular news briefing.

Japan announced in September 2012 that it would "purchase" the Diaoyu Islands despite strong opposition from China. It has frequently sent vessels and planes to detect Chinese ships and planes in regular navigation or training, which has severely hampered the freedom of navigation and overflight, Yang said.

Japanese Coastguard warships intruded into the drill area of the Chinese navy on the high seas and interfered in their normal military exercise, Yang said.

Japan also boosted its military capacity under various disguises, attempting to change the post World War II international order. Japanese authorities play up the so-called China threat through the media and openly create confrontations, Yang said.

"Who is changing the status quo, accelerating regional tension, confrontation and jeopardizing regional security? I think the international community will make a fair judgement," the spokesman said.

Japan established its own ADIZ in 1969, therefore it has no right at all to make irresponsible remarks on China's ADIZ over the East China Sea, said Yang.

Japanese Prime Minister Shinzo Abe said on Monday that Japan was seriously concerned over the "unilateral" setup of the ADIZ and urged China to "retract the decision."

"Should the decision be retracted, we ask the Japanese side to revoke its ADIZ first, we will then consider their demand 44 years later," Yang said.