TOKYO (REUTERS) - US President Barack Obama arrives in a tense Asian region on Wednesday, faced with the delicate task of assuring Japan and other regional allies of America's commitment to their defence without hurting Washington's vital ties with a rising China.
That difficult diplomatic balancing act was highlighted on Monday, when Japanese Prime Minister sent a ritual offering to Tokyo's Yasukuni Shrine, seen in parts of the region as a symbol of Japan's past militarism.
The move strained Tokyo's already tense ties with China and fellow US ally South Korea, another stop on his four-nation tour that will also take in Malaysia and the Philippines.
Japan, for its part, has been beset by anxiety over the degree to which reality matches rhetoric in Obama's promised"pivot" of US military and diplomatic assets to Asia.
Abe and Obama will be keen to send a message that the alliance - central to America's presence in Asia and the core of Tokyo's security policy - is stronger then ever when they hold their symbolic summit on Thursday. "The fundamental message the two leaders are trying to send is solidarity in the face of China's assertive behaviour, and I expect that message to be fairly clear," said a former Western diplomat. "In that sense, an element of success is very likely."
The two leaders are also likely to discuss how to deal with North Korea at a time when the region is jittery over a possible nuclear test by an unpredictable Pyongyang.
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 the North's 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".
US-Japan relations were strained after Abe in December visited the Yasukuni Shrine, where wartime leaders convicted as war criminals by an Allied tribunal are honoured along with war dead. The visit prompted a US statement of "disappointment".
Abe has since sought to soothe US 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 US, that the message has been received," the ex-diplomat said. "To that degree, the situation is different from some months back."