The Pentagon's leadership on Wednesday offered a possible way for China to defuse the crisis over airspace control that has led both sides to flex their military might in the East China Sea.
Defense Secretary Chuck Hagel said the U.S. was looking at "mechanisms" to avoid a confrontation over China's declaration of an Air Defense Identification Zone over wide swaths of the East China Sea to include uninhabited islands claimed by Japan and China.
One of those mechanisms might be for China to make a distinction between aircraft bound for China intending to enter Chinese sovereign airspace and those intending to fly through international air space included in the ADIZ to other destinations, said Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff.
China has demanded that all aircraft, both military and commercial, file flight plans and identify themselves in the ADIZ. Dempsey said U.S. concerns might be eased if the Chinese limited their demands to aircraft bound for China, which already must file flight plans.
"We're not talking about sovereign airspace here but international air space," Dempsey said at a Pentagon briefing with Hagel. Currently, the Chinese have been making demands on aircraft "regardless of whether they're entering sovereign airspace, and that is de-stabilizing."
Last week, the U.S. sent two B-52 bombers through the ADIZ to demonstrate that the U.S. military would not recognize the zone, and China has dispatched fighters to monitor air traffic.
Despite the dispute, Hagel said the U.S. military was continuing to pursue a closer relationship with the People's Liberation Army, but "it's probably not going to get any less complicated in the East China Sea.
"These are combustible issues," Dempsey said.
Hagel and Dempsey spoke as Vice President Joe Biden met with Chinese President Xi Jinping in Bejing, where Biden received a mixed message on the ADIZ issue that has put all of south Asia on edge.
In public, Biden and Xi spoke in generalities.
"Enhancing dialogue and cooperation is the only correct choice for us," the Chinese president said before going into private meetings with Biden that were originally scheduled for 45 minutes but extended to more than two hours.
The official Chinese media took a tougher line, publishing photo spreads of China's growing military arsenal and blaming Japan for the faceoff over the islands and the airspace.
"A wise and far-sighted Washington should choose to play a constructive role in the region to stop indulging Japan's recklessness in exchange for a mess of pottage, and to persuade the island nation not to go too far," said a commentary in the official Chinese news agency Xinhua.
In a stop in Tokyo before arriving in Beijing, Biden stressed the U.S. commitment to the mutual defense treaty with Japan.
"We, the United States, are deeply concerned by the attempt to unilaterally change the status quo in the East China Sea," Biden said after meeting with Japanese Prime Minister Shinzo Abe. "This action has raised regional tensions and increased the risk of accidents and miscalculation."
Biden's next stop Thursday will be in South Korea, which has its own territorial disputes with China. The U.S. is also concerned that Seoul might declare its own air identification zone in response to China's action.
The diplomatic fallout from China's aggressive actions also dimmed prospects for another round of the so-called "six-party talks" involving the U.S., Japan, China, Russia and North and South Korea on reining in North Korea's nuclear ambitions.
"There had been a lot of consultation on the prospects of coming back to the six-party talks … [but] that opportunity I think has been lost by the focus on the ADIZ," said Scott Snyder, a senior fellow for Korea studies at the Council on Foreign Relations.
