WASHINGTON, D.C. - Vice President Joseph Biden embarked for the capitals of Japan, China, and South Korea today as the three nations stand off over the new flight restrictions Beijing unilaterally imposed in the East China Sea.

The trip comes eight days after Beijing announced it would require all aircraft traveling through the zone to identify itself to Chinese authorities, report its flight plan, and yield to orders from that country or else face the possibility of "defensive emergency measures."

Biden is scheduled to land in Tokyo Monday and meet with the presidents and prime ministers of each Pacific power during the week-long trip to discuss the area widely recognized as international airspace. It includes tiny Ieodo Island, currently controlled by South Korea, and a set of long disputed islands administered by Japan but claimed by China and Taiwan - known as Diaoyu in China and Senkaku in Japan.

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On ABC's This Week National Security Adviser Tom Donilon was asked why the U.S. should care about the islands, which are mostly uninhabited.

"In this current incident, if the United States were not present, if the United States didn't take the action it is taking in terms of consulting and coordinating with our allies [...] you could see tension rising to a really dangerous level," he said.

The Philippines, Malaysia, Brunei and Vietnam also have claims in the affected region, known as an Air Defense Identification Zone (ADIZ.)

The White House suggests Biden's personal relationship with Chinese President Xi Jinping, whom he is scheduled to meet Wednesday, could help ease the friction. One senior administration official said the vice president, "knows President Xi as well or better than probably any American, and possibly virtually any leader. So this matters."

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The Pentagon has condemned the ADIZ as a "destabilizing" move that "raises the risk of misunderstanding and miscalculation." But it has not stopped the U.S. military from continuing drills inside the zone, including re-fueling training by two B-52 bombers last Tuesday and a joint naval exercise with Japan Friday.

Regardless, Biden's diplomatic tour has been long planned and follows a similar trip the vice president took to Asia over summer. Secretary of State John Kerry and Defense Secretary Chuck Hagel, among other cabinet members, have also visited the continent in recent months as the Obama administration continues to shift attention eastward.

The vice president's itinerary also includes events highlighting the role of Japanese women in the economy with Ambassador Caroline Kennedy, a keynote address at Seoul's Yonsei University, meetings with U.S. and South Korean troops and a visit to the demilitarized zone.