US President Barack Obama has assured Japan that islands at
the center of its territorial dispute with China are covered by a bilateral
defense treaty.
In an interview ahead of his Asian tour, Mr Obama said the
US would oppose any attempt to undermine Japan's control over the islands.
US officials have made such comments in the past, but this
is the first time Mr Obama has given such explicit support.
He arrived in Japan on Wednesday ahead of stops in three
other Asian nations.
China's foreign ministry has said it opposes the islands
being covered by the defense treaty.
"The so-called US-Japan alliance is a bilateral
arrangement from the Cold War and ought not to harm China's territorial
sovereignty and reasonable rights," spokesman Qin Gang said in Beijing
during a regular press briefing.
Mr Obama is not going to Beijing, but relations with China
are expected to dominate his meetings with regional leaders.
The trip was an opportunity to reinforce the importance the
US placed on Asia, former US Assistant Secretary of State PJ Crowley told the
BBC.
"Many traditional allies... [also] value a strong US
presence in the region to balance against an assertive China," he said.
The visit comes amid a "period of very significant
tension among American allies, and between American allies and China", he
added.
'Clear position'
Mr Obama's trip - from 23-29 April - comes nearly seven
months after he cancelled a visit to the region due to a government shutdown.
He will have a private dinner with Japanese Prime Minister
Shinzo Abe, as well as bilateral meetings with the South Korean, Malaysian and
Philippine leaders.
Ties between Tokyo and Beijing were expected to be high on
the agenda as Mr Obama touched down in Tokyo on Wednesday evening.
Relations are severely strained over a raft of issues,
including East China Sea islands - called Senkaku in Japan and Diaoyu in China
- that both claim.
Japan controls the islands but Chinese ships have sailed
repeatedly in and out of what Japan says are its territorial waters as Beijing
presses its claim. Last year, China declared an air defence identification zone
over the islands, drawing widespread criticism.
Ahead of his visit, Mr Obama said in a written response to
Japan's Yomiuri newspaperthat the US opposed "any unilateral attempts to
undermine Japan's administration of these islands".
"The policy of the United States is clear - the Senkaku
Islands are administered by Japan and therefore fall within the scope of
Article 5 of the US-Japan Treaty of Mutual Co-operation and Security," he
wrote.
How will US trade deal affect Japan's economy? Linda Yueh
reports
Japan depends on the US for its security, under a
decades-old alliance that dates back to the end of World War Two.
The US, however, is keen for Japan to take on greater
responsibility for its own security - an area where Mr Obama and Mr Abe are
likely to be in general agreement.
The two leaders are also expected to discuss the 12-nation
Trans-Pacific Partnership (TPP), a trade deal which requires each country to
strike an agreement with other prospective members.
A rift between Japan and the US over agriculture product
tariffs has proved a major sticking point.
Mr Obama is also expected to have to balance bolstering US
ties with each Asian ally with improving communication among them, particularly
between South Korea and Japan.
The two Asian nations are at odds over a separate set of
disputed islands, as well as historical issues linked to Japan's war history.
The Japanese prime minister's views on World War Two have
poisoned relations to the point where Tokyo and Seoul are now barely on
speaking terms, reports the BBC's Rupert Wingfield-Hayes in Tokyo.
On Tuesday, Seoul accused Mr Abe of romanticising
"Japanese colonialism and its war of aggression" after he sent an
offering to the Yasukuni Shrine, where Japan's war dead - including convicted
war criminals - are enshrined.
But the US - which last month brokered a meeting of the
Japanese and South Korean leaders - wants the two to co-operate on North Korea,
amid long-term deadlock in moves to end Pyongyang's nuclear ambitions.
On Tuesday, South Korea's defence ministry said that it had
detected "a lot of activity" at the Punggye-ri nuclear test site.
North Korea could be planning to hold a "surprise
nuclear test or just pretend to stage a nuclear test", a spokesman said.
Mr Obama arrives in Seoul on Friday. A state department
spokeswoman said the US was "closely monitoring the situation". The
test, if it went ahead, would be North Korea's fourth.