David Lerman
Bloomberg News

Vice President Joe Biden will press Chinese leaders on their intentions with a new air-defense zone, as Defense Secretary Chuck Hagel assured Japan of U.S. support and continued military operations in the region.

Biden will use meetings with leaders in Beijing next week partly to express U.S. concern about China’s behavior toward its neighbors and seek an explanation of the air zone it claimed over disputed areas of the East China Sea, according to an administration official who briefed reporters Wednesday on condition of anonymity to discuss the vice president’s plans.

China’s establishment of an air zone that includes islands claimed by both Japan and China “is a potentially destabilizing unilateral action designed to change the status quo in the region, and raises the risk of misunderstanding and miscalculation,” Hagel said in a call Wednesday to Japanese Defense Minister Itsunori Onodera, according to an e-mailed statement by Pentagon spokesman Carl Woog.

The U.S. sent two unarmed B-52 bombers through the disputed zone this week without the advance notice that China has demanded and without incident. South Korea’s military sent a plane through the area Tuesday on a regular patrol flight, according to NHK, Japan’s public broadcasting organization, which cited military sources it didn’t name.

ANA Holdings Inc. and Japan Airlines Co., Japan’s largest carriers, ran flights that landed Wednesday through the zone without advance notice, the companies said. Peach Aviation Ltd., a low-fare affiliate of ANA, also flew through the area without coordinating with the Chinese.

The perils of in-air confrontations are illustrated by a 2001 incident when a Chinese fighter jet collided with a U.S. Navy plane monitoring Chinese communications over the South China Sea. The Chinese pilot was killed, while the U.S. plane made an emergency landing on China’s Hainan island. China held its crew of 24 for 11 days before freeing them after the U.S. expressed regret for the death of the Chinese pilot.

Dispute overshadows trade

Biden’s trip to China, Japan and South Korea on a visit to promote trade and other joint interests risks being overshadowed by the dispute over the air zone China declared on Saturday. The official who briefed reporters declined to say whether Biden would call on China to eliminate the zone, saying any remedial actions would be discussed through private diplomatic channels.

China’s move marked the latest escalation between the world’s second and third-largest economies over islands — known as Senkaku in Japanese and Diaoyu in Chinese — located in the zone. More than a year since Japan infuriated China by buying some of the islands from a private owner, planes and ships from the two countries have frequently tailed each other in the area.

The risk of shots being fired in a Japan-China dispute over the islands is “a no-kidding threat to growth and confidence” in the region, Robert McNally, former senior director for international energy on National Security Council, said in a phone interview.