The creation of an "Air Defense Identification Zone" by China comes amid increasing tensions between Beijing and Tokyo over competing claims to disputed islands in the sea, which are believed to be situated near large reserves of natural resources.
China's announcement Saturday of the zone, which it described as an early-warning system for self-defense, drew a swift response from the United States, Japan's closest military ally.
Washington warned that the latest Chinese move creates the risk of potentially dangerous miscalculations in the sensitive region, where Chinese and Japanese ships and planes have already been involved in tense encounters.
"This unilateral action constitutes an attempt to change the status quo in the East China Sea. Escalatory action will only increase tensions in the region and create risks of an incident," U.S. Secretary of State John Kerry said.
"We have urged China to exercise caution and restraint, and we are consulting with Japan and other affected parties throughout the region," Kerry said. The United States has thousands of troops stationed in Japan as part of a security treaty between the two allies.
But Chinese officials dismissed the U.S. comments as unjustified interference.
American criticism of the air zone announcement is "completely unreasonable," Col. Yang Yujun, a Ministry of National Defense spokesman, said Sunday.
The United States should stop taking sides on the issue, cease making "inappropriate remarks" and not send any more "wrong signals" that could lead to a "risky move by Japan," he said.
Beijing demands that the United States respect Chinese national security, stop making "irresponsible remarks" about the air defense identification zone and make "concrete efforts" for peace and stability in the Asia-Pacific region, Yang said.
The Chinese Ministry of Foreign Affairs said it had lodged a representation with U.S. Ambassador Gary Locke asking the United States "to correct its mistakes immediately."