美国国务卿第五次访问亚洲

U.S. Secretary of State John Kerry is set to arrive in Seoul, the first stop on his latest three-nation trip to Asia. Kerry will head to Beijing this weekend, and then fly on to Indonesia.

It's Kerry's fifth trip to East Asia since taking office last year, and comes as tensions in the East and South China seas continue to rise. Meanwhile, the U.S.'s key ally in the region, Japan, has enraged many of its neighbors through a number of recent actions, that some say is a clear sign the country is moving swiftly towards a new level of nationalism.

Kerry has travelled to the Middle East over a dozen times and the absence of U.S. President Barack Obama at last year's Asia-Pacific Economic Cooperation meeting has led allies in the region to question U.S. commitment to rebalancing its policy in the Asia-Pacific.

"Everyone can see that his main interest is the broader Middle East. That's where he has been spending most of his time and that essentially invalidates the basic logic of the rebalance," said Michael O'Hanlon at Brookings Institution.

Recently Kerry has sought to reaffirm the U.S. commitment to Japan last week standing next to Foreign Minister Fumio Kishida. He also rejected China's Air Defense Identification Zone, or ADIZ.

"The United States neither recognizes nor accepts China’s East China Sea ADIZ," Kerry said.

That created a strong reaction in Beijing, accusing the U.S. of irresponsible remarks. The ADIZ issue raged during December's visit by U.S. Vice President Joe Biden - as yet no agreement between Washington and Beijing.

Both Seoul and Beijing no doubt will want to express their anger to Japan's closest ally over Prime Minister Shinzo Abe's recent visit to the Yasukuni Shrine which honors war criminals among Japan's war dead. The Democratic People's Republic of Korea will also dominate discussions in both capitals. Kerry may also be asked to explain the exact nature of Washington's pledge to upgrade its security relationship with Japan.

In Indonesia, the U.S. will seek closer cooperation with the world's largest Muslim nation and greater cooperation between Washington and the Association of Southeast Asian Nations. The issue of territorial claims in the South China Sea is also likely to come up. And while allies from the Philippines to Japan may be worried about the commitment of the U.S. to the so-called "Asia pivot", political analysts say when U.S. core interests are at stake it is ready to act.

"We still have the world's most powerful navy in the Asia Pacific region. We do still have a defense budget of pushing $600 billion dollars a year - we still have 35,000 U.S. troops in Afghanistan and we still have a commitment not to let Iran get a nuclear weapon so there are numerous signs of American resoluteness," O'Hanlon said.

There will be one more country that Kerry will visit on this trip, the United Arab Emirates. Even though Asian issue will be sent to stage, he thinks he can squeeze one more trip to the Middle-East before heading back to Washington.