Vice President Joe Biden is preparing to head to Beijing Wednesday, following talks in Japan about China's controversial Air Defense Identification Zone, or ADIZ.
After meeting Tuesday with Prime Minister Shinzo Abe, Biden told reporters the announcement of the new zone "has raised regional tension and increased the risk of accidents and miscalculations."
He said he intends to raise the issue of the ADIZ when he meets with Chinese leaders in Beijing.
In an interview in Tokyo, Biden urged both Japan and China to "establish crisis management and confidence-building measures to lower tensions." But Bonnie Glaser, a China expert at the Washington-based Center for Strategic and International Studies, says that is going to be difficult right now.
China late last month set up its Air Defense Identification Zone, which overlaps with islands also claimed by U.S. ally Japan. Beijing has requested that all planes submit flight plans ahead of flying through the zone.
Speaking from Beijing, James Manicom, a research fellow at the Canada-based Center for International Governance Innovation, says China's ADIZ differs from zones imposed by other countries in one major way.
"They apply the zone to any aircraft that are even transiting the zone," he said, explaining that countries with similar air defense zones such as the U.S., Canada, Iceland and the UK typically apply requirements only to aircraft that intend to enter their airspace.
"That's the problem," he said. "It exceeds what other countries believe to be a responsible lien, if you like, on freedoms of international airspace."
Repeatedly rejecting the Chinese zone, the U.S. flew two unarmed B-52 bombers on "routine" training missions through the area last week, ignoring Chinese demands the aircraft identify themselves.
But Washington officials have recommended U.S. commercial airlines comply with China for the safety and security of passengers.
After visiting China on Wednesday, Biden will head to South Korea Thursday, which has also been angered by China's declared air defense zone.
He is expected to meet with President Park Geun-hye and visit the demilitarized zone with the North before returning to Washington.