There was a flurry of protests and official statements during the weekend from all sides arising from China's surprise announcement that it has set up an East China Sea "Air Defense Identification Zone" that encompasses the Senkaku Islands, which Japan controls and has covered with an air defense zone of its own. The islands, which are also claimed by China, are a source of bitter dispute between Tokyo and Beijing, and the latest step by China is seen as further escalating the tensions.
In a strongly worded statement Saturday, Secretary of State John Kerry said the United States is "deeply concerned" about China's announcement. He warned China its "unilateral action" is an attempt to change the status quo in the East China Sea and that such escalatory action will "only increase tensions in the region and create risks of an incident."
The secretary also said freedom of over flight and other internationally lawful uses of sea and airspace are essential to prosperity, stability and security in the Pacific.
"We don't support efforts by any state to apply its ADIZ procedures to foreign aircraft not intending to enter its national airspace," Kerry's statement said. "The United States does not apply its ADIZ procedures to foreign aircraft not intending to enter U.S. national airspace. We urge China not to implement its threat to take action against aircraft that do not identify themselves or obey orders from Beijing."
Under the defense zone umbrella, China can identify and may even take military action against planes near the islands in the East China Sea. The islands also are claimed by Taiwan.
Separately, Japan lodged a protest with China. Junichi Ihara at the Japanese Foreign Ministry told Han Zhiqiang, senior diplomat at the Chinese Embassy, on phone that the Chinese action may escalate current bilateral tensions over the Senkaku Islands, which China refers to as Diaoyu, Kyodo News reported.
A senior Japanese Defense Ministry official called Beijing's move an "action to demonstrate that the Senkakus are their territory."
China in turn lodged its own protests against the United States and Japan.
Chinese Foreign Ministry spokesman Qin Gang said Assistant Foreign Minister Zheng Zeguang in his representation with U.S. Ambassador Gary Locke asked the United States "to correct its mistakes immediately and stop making remarks irresponsibly," the official media said.
Qin was quoted as saying AIDZ complies with the United Nations Charter and international practices.
"Its aims are to protect China's state sovereignty and territorial and airspace safety," he said, adding the move "aims at no specific nation or target and will not affect the freedom of over-flight in relevant airspace."
The Foreign Ministry spokesman repeated China's stand that the Diaoyu and its surrounding islets are an inherent part of the Chinese territory and China "will firmly defend the territorial sovereignty over the Diaoyu islands," and that the current situation is derived "from the wrong words and deeds of the Japanese side."
Qin also said Japan's remarks are "groundless and utterly wrong."
The maritime territorial dispute over the uninhabited islands escalated more than a year ago after the Japanese government purchased three of the five main islands in the Senkaku group from a private Japanese owner.
The New York Times said Japan's refusal to accept China's AIDZ indicated Japan would not back down from its stand. The Times quoted analysts that a miscalculation or an accident resulting form the dispute could trigger an armed confrontation which could drag the United States into it.
U.S. Defense Secretary Chuck Hagel was quoted as saying the United States would stand by its security treaty obligations to aid Japan if it were attacked.
For now, the Times said both the United States and Japan want to determine if China's move is merely designed for domestic consumption.
The Wall Street Journal, quoting a senior U.S. official Sunday, said there were no immediate plans to fly American planes into the expanded air defense identification zone.
"We will ensure our view of how the U.S. operates in that area is clear," the official said. "At some point there will be something to demonstrate that."
The Journal quoted foreign military officials and analysts that the Chinese military has little experience in conducting interceptions farther from its territory. The report also quoted a senior U.S. official that China's move was unexpected and surprising as top U.S. officials were busy working on the interim deal with Iran.
Some analysts told the Journal they expect China to eventually set up a similar ADIZ over the South China Sea.
China's claims over the South China Sea issue is already a matter of deep concern to neighboring countries including Vietnam, Malaysia, Taiwan, Brunei and the Philippines.