U.S. President Barack Obama prepares to board Air Force One to depart Andrews Air Force Base outside Washington to begin his seven-day four-nation Asian tour, April 22, 2014.
U.S. President Barack Obama has said Washington welcomes China's rise but that engagement with Beijing would not come at the expense of its Asian allies - as Chinese state media greeted his imminent arrival in the region with a broadside accusing the United States of wanting to "cage" the emerging superpower.
Obama's remarks, aimed at reassuring Japan and other allies, set against a robust commentary from China's state news agency Xinhua that also called the United States "myopic", demonstrate the delicate balancing act Obama faces on a week-long Asia tour.
The four-nation trip that starts in Tokyo later on Wednesday comes at a time of rising tension in the region, and as the United States urges Japan's unpredictable neighbor North Korea not to conduct another nuclear test.
Obama, who will be making the first full state visit to Japan by a U.S. President since 1996, must assuage worries by Tokyo and other allies that his commitment to their defense in the face of an increasingly assertive China is weak, without hurting vital U.S. ties with Asia's biggest economy.
Noting Beijing and Washington could work together on issues such as North Korea's nuclear program, Obama told the Yomiuri newspaper, in written remarks: "In other words, we welcome the continuing rise of a China that is stable, prosperous and peaceful and plays a responsible role in global affairs."
He added: "And our engagement with China does not and will not come at the expense of Japan or any other ally."
Such assurances are likely to be high on the agenda when Obama meets Japanese Prime Minister Shinzo Abe at a symbolic summit on Thursday.
Japan, whose ties with rival China have chilled over the past two years, has been beset by anxiety over the degree to which reality matches rhetoric in Obama's promised "pivot" of U.S. military and diplomatic assets to Asia.
China, for its part, fears the U.S. is pursuing a policy of containment through its network of Asian allies, several of whom have long-standing territorial disputes with Beijing in the East and South China Seas.
Wednesday's Xinhua commentary criticized U.S. policy in the region as "a carefully calculated scheme to cage the rapidly developing Asian giant".
"The United States should reappraise its anachronistic hegemonic alliance system and stop pampering its chums like Japan and the Philippines that have been igniting regional tensions with provocative moves," it said.
Obama and Abe are expected to send a message of solidarity after strains following Abe's December visit to Tokyo's Yasukuni Shrine, seen by critics as a symbol of Japan's past militarism.
Obama also assured Japan that tiny isles in the East China Sea at the heart of a territorial row with China are covered by a bilateral security treaty that obligates America to come to Japan's defense. That is long-stated U.S. policy, but the confirmation by the president is likely to be welcome in Japan.
"The policy of the United States is clear - the Senkaku islands are administered by Japan and therefore fall within the scope of ... the U.S.-Japan Treaty of Mutual Cooperation and Security," Obama said, using the Japanese name for the islands that are known as the Diaoyu in China, which also claims them.
"And we oppose any unilateral attempts to undermine Japan's administration of these islands," he said.
Japanese and Chinese naval vessels and coastguard ships have played cat-and-mouse around the disputed islets since Japan's government bought the then-privately owned territory in 2012.
A joint statement to be issued at the summit will state the two allies will not tolerate any attempt to change the status quo by force - a phrase that implicitly targets China - but likely not mention the islands or China by name, Japanese media have reported.
Nuclear North Korea
Obama also reaffirmed Washington's commitment to the security of South Korea, and said it would stand firm in its insistence that a nuclear North Korea was unacceptable.
Seoul is the second stop on Obama's four-nation swing, which also includes Malaysia and the Philippines.
"The burden is on Pyongyang to take concrete steps to abide by its commitments and obligations, and the United States, Japan and South Korea are united in our goal - the complete denuclearization of the Korean peninsula," Obama said.
North Korea, already subject to United Nations' sanctions over its previous atomic tests, the third and most recent of which took place in early 2013, threatened last month to conduct what it call "a new form of nuclear test".
On Monday its KCNA news agency quoted a foreign ministry spokesman saying Obama's trip was a "reactionary and dangerous one as it is aimed to escalate confrontation and bring dark clouds of a nuclear arms race to hang over this unstable region".
The United States said on Tuesday it was watching the Korean peninsula closely after news reports quoted the South Korean government as saying that heightened activity had been detected at North Korea's underground nuclear test site.
"We continue to urge North Korea to refrain from actions that threaten regional peace and security and to comply with its international obligations and commitments," State Department spokeswoman Jen Psaki told a regular briefing.
History and trade
U.S.-Japan relations were strained after Abe in December visited the Yasukuni Shrine, where wartime leaders convicted as war criminals by an Allied tribunal are honored along with war dead. The visit prompted a U.S. statement of "disappointment".
Abe has since sought to soothe U.S. concerns that his conservative agenda to recast wartime history with a less apologetic tone is blocking improved ties with Seoul and giving China ammunition to paint him as reviving past militarism.
Last month, Abe told parliament that he has no plans to revise a landmark 1993 apology to women, many Korean, forced to work in Japan's wartime military brothels.
And while he sent a ritual offering to Yasukuni on Monday, Abe did not join the nearly 150 lawmakers who visited in person to commemorate its spring festival.
"Abe, by declining to visit Yasukuni for the spring festival, sent the message that he has heard the U.S., that the message has been received," a former Western diplomat said. "To that degree, the situation is different from some months back."
The two leaders will also need to show progress towards a two-way trade pact seen as vital to a broader U.S.-led Trans-Pacific Partnership (TPP) deal.
The deal is both a pillar of Obama's Asia rebalancing and critical to Abe's strategy to revive the Japan's economy.
But significant gaps remain over Japan's desire to keep tariffs on politically sensitive farm products such as beef.
Failure could take the wind out of the push for a broader agreement among the 12-nation TPP group that would stretch from Asia to Latin America.
Some trade experts said that despite the hurdles, a last-minute agreement could not be ruled out.
U.S. Trade Representative Michael Froman had arrived in Japan earlier than expected and was likely to meet Japanese Economy Minister Akira Amari, Japanese media reported on Wednesday.