BEIJING - U.S. Ambassador to Japan Caroline Kennedy today sharply criticized China for recent actions she blames for escalating tension in the region.

"Unilateral actions like those taken by China with their announcement of an East China Sea Air Defense Identification Zone undermine security and constitute an attempt to change the status quo in the East China Sea," she said. "This only serves to increase tension in the region."

Over the weekend China announced its right to monitor the airspace over a new ADIZ that includes the disputed island territories known as Diaoyu in China and Senkaku in Japan. China demanded that all aircraft register with China prior to any flight in the area. On Tuesday the U.S directly defied China by flying two, unarmed B-52 bombers into the territory. Pentagon officials maintained the flight was planned in advance and not in direct response to China's recent actions.

Shuji Kajiyama/Pool/AP Photo

China responded angrily today through an editorial in the state-run newspaper China Daily. "Washington is barking up the wrong tree," the editorial stated. "The Japanese and U.S. hysteria is unnecessary, and potentially dangerous, because it is based on a serious misreading, if not intentional distortion, of Chinese strategic purposes." China's Defense Ministry also said it had "monitored the entire progress of two unarmed U.S. B-52 bombers," and, "has the ability to effectively manage and control the relevant airspace."

Kennedy, who only recently became ambassador to Japan, said the U.S. "will continue to consult closely with the Japanese government on these issues and I know Vice President Biden will be underscoring these messages on his visit next week."

Biden will be visiting Japan, China and South Korea during a five day visit that will begin in Tokyo on Dec. 2. A senior administration official said the timing of Biden's trip gives him the opportunity to discuss the issue with political leaders, directly convey U.S. concerns and seek clarity regarding Chinese intentions in making this move at this time."