Hong Kong: The Chinese government on Saturday claimed the right to identify, monitor and possibly take military action against aircraft that enter a newly declared “air defence identification zone,” which covers sea and islands also claimed by Japan and threatens to escalate an already tense dispute over some of the maritime territory. The move appeared to be another step in China’s efforts to intensify pressure on Japan over Japanese-controlled islands in the East China Sea that are at the heart of the dispute. The declaration, from a Chinese Ministry of National Defense spokesman, Col. Yang Yujun, accompanied the ministry’s release of a map, geographic coordinates and rules that Colonel Yang said authorized treating an area alongside the eastern Chinese coast as the air defence identification zone.

“The objective is to defend national sovereignty and territorial and air security, as well as to maintain orderly aviation,” Colonel Yang said in comments issued on the ministry’s website in both Chinese and English. “China’s armed forces will take defensive emergency measures to respond to aircraft that do not cooperate in identification or refuse to follow orders,” said the rules issued by the ministry. Later on Saturday, China’s air force said it had dispatched its first planes, including fighter jets, to enforce the rules. The Chinese announcement follows months of increasing tension over the uninhabited islands as China appeared to be taking moves to establish its claim to them, including more frequent patrols by ships around the islands. Those patrols have led to cat-and-mouse games between Chinese and Japanese ships near the islands, known as the Senkaku by Japan and the Diaoyu in China.

But the claim to the airspace near the islands could prove particularly problematic. Japan has scrambled fighter jets in the past when China has sent a plane, and possibly a drone, to the area, to ensure that they were not entering what Japan considers its airspace. As the potential for a miscalculation that leads to conflict has increased, the United States has become worried that as an ally of Japan, it could be dragged into any conflict with China.