US Vice President Joe Biden, speaking from Tokyo on Tuesday, called on China and Japan to find a way to reduce tensions over China's air defense zone.
He added that Washington was "deeply concerned" by China's declaration of the zone, which includes disputed islands that both countries lay claim to.
"This action has raised regional tensions and increased the risk of accidents and miscalculation," Biden said, while speaking alongside Japanese Prime Minister Shinzo Abe.
"This underscores the need for crisis management mechanisms and effective channels of communication between China and Japan to reduce the risk of escalation," he added.
Biden said he planned to raise Washington's concerns to China's leaders when he met them later this week.
China's vice foreign minister said Tuesday that the United States, Japan and South Korea shouldn't "read too much into and overreact" to China's air defense zone.
Speaking in Beijing, Liu Zhenmin said, "China's activities in the area and the legitimate exercise of its jurisdiction should not be viewed as an attempt to change the status quo."
On his trip, Biden seeks to calm tensions between China and Japan, while reassuring Japan of the United States' support in the territorial dispute over islands in the East China Sea.
The White House said Biden's trip would also emphasize Washington's "enduring presence as a Pacific power... and underscore our commitment to rebalancing US foreign policy towards the Asia-Pacific."
On Monday, Japan reiterated that both Tokyo and Washington rejected China's air defense identification zone in the East China Sea, which includes the disputed Senkaku islands (known as Diaoyu in China).
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"The US government has made it clear that it is deeply concerned about China's establishment of the air defense identification zone, and that it will not accept China's demands regarding operations in the zone," Japanese Chief Cabinet Secretary Yoshihide Suga said during a news conference.
Three American airlines plan to notify China of their flight plans, upon advice from the government. However, Washington said this did not indicate acceptance of the air defense zone.
Japan's airlines will not submit their flight plans to China, upon the Japanese government's request.
"The prospect of a planned war between these two countries is slight," Dr. John Lee, an expert on energy security at the University of Sydney, told GlobalPost in November. "But the prospect of an unintended escalation, stemming from an incident at sea is significant."
The United States has no stance on the disputed islands, but acknowledges Japan's administrative control over them. In case the issue ended in military conflict, Washington would come to Tokyo's aid.
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