(AP) Hours after touching down in Asia on a long-planned trip, U.S. Vice President Joe Biden is being pulled into a messy territorial spat between China and its neighbors.
Biden is meeting in Tokyo on Tuesday with Japanese Prime Minister Shinzo Abe, whose government is pressing the U.S. to more actively take Japan's side in an escalating dispute over China's new air defense zone above a set of contested islands in the East China Sea.
Although the U.S. has joined Japan and other allies in refusing to recognize the zone, Washington has treaded carefully, wary of creating a new fault line in its relationship with China just as the U.S. is pursuing a new era of economic cooperation with Beijing.
Whether Biden and Abe appear to be in lockstep will be closely watched by China, as well as other Asian nations worried that the new defense zone may portend further steps by China to assert control in the region. On Monday, China's ambassador to the Philippines claimed China has a sovereign right to establish a similar zone over the South China Sea, where China and the Philippines are locked in another long-running territorial dispute.
"We remain deeply concerned by the announcement," Biden said in a written interview with Japan's Asahi Shimbun newspaper.
The zone covers more than 600 miles from north to south, above international waters separating China, South Korea, Japan and Taiwan. China says all aircraft entering the zone must notify Chinese authorities beforehand or face unspecified defensive measures.
Whether commercial airliners should abide by that requirement emerged as a point of conflict between the U.S. and Japan as Biden headed to Tokyo.
Reluctant to cede any ground, Tokyo has urged Japanese commercial flights not to notify China before flying through the zone. Word that the U.S. had advised American commercial carriers to comply rankled leaders in Tokyo, who are hoping a united front with the U.S. will increase pressure on Beijing to reverse course.
Pushing back on the notion there was any disagreement between the U.S. and Japan, senior Obama administration officials said Tuesday that the U.S. never told American commercial carriers to comply specifically with China's demands. The Federal Aviation Administration merely reaffirmed existing policy that pilots should comply with such instructions anywhere in the world, said the officials, who weren't authorized to comment by name and demanded anonymity.
Still, the U.S. move gave China an opening to suggest the U.S. was acquiescing to its assertion of authority over the airspace.
Chinese Foreign Ministry spokesman Hong Lei on Monday praised what he said was a "constructive attitude and cooperative will" demonstrated by U.S. airlines' willingness to file their flight plans with China. He contrasted that with what he called "malicious hype" and "erroneous actions" by Japan in refusing to tell its pilots to comply with the zone.
The feud promises to trail Biden throughout his weeklong trip to Asia a tour intended to affirm Washington's continued interest in upping its presence in the region, in part to counter China's growing influence.
After a working dinner with Abe on Tuesday night, Biden will fly to Beijing on Wednesday to meet with Chinese President Xi Jinping, where officials said Biden would raise U.S. concerns over the zone directly. Biden will then travel Thursday to South Korea another U.S. ally at odds with China over the air defense zone.
Japan, which claims the islands as its own, is concerned that compliance with China's demands will allow China to slowly solidify its claim to the tiny islands and the strategically important waters that surround them. The United States sees rising tensions between China and its neighbors as a threat to U.S. interests, and is concerned that the tense atmosphere increases the likelihood of an incident in the air spiraling out of control.
U.S. officials said Biden will tell China's leaders that America's commitment to its allies is beyond question. Although the U.S. doesn't take a position on the islands' sovereignty, U.S. officials acknowledge that Japan administers the islands, meaning U.S. treaty obligations to defend Japan could come into play.
After a morning meeting with Japanese lawmakers and Deputy Prime Minister Taro Aso, Biden made his way to Shibuya, a bustling Tokyo district and fashion center, where he toured a technology company founded by a female entrepreneur to highlight the role of women in Japan's economy. U.S. Ambassador to Japan Caroline Kennedy joined Biden as he mingled with young employees in a chic, 24th floor lunchroom overlooking Tokyo's sprawling skyline.
Also on Biden's agenda in Tokyo is a major trade agreement with Japan and 10 other nations that the U.S. hopes to complete by the end of 2013. Japan's concerns about removing steep agricultural tariffs and increasing access to its auto markets have become flashpoints in those negotiations. In another potential complication, Japan said Monday that its economy minister involved in the trade talks has been hospitalized for tests.
Associated Press writer Christopher Bodeen in Beijing contributed to this report.
Reach Josh Lederman at http://twitter.com/joshledermanAP