Japanese and US foreign and defence ministers huddled Thursday to renew their security alliance as an emboldened Tokyo looks to push back against regional threats and the growing might of China.
US Secretary of State John Kerry, Secretary of Defense Chuck Hagel, Japanese Foreign Minister Fumio Kishida and Defence Minister Itsunori Onodera -- held the first review of the cornerstone alliance in 16 years.
"This alliance, which we believe is a linchpin alliance for the United States in the region, has not been updated since 1997, " Kerry said at the start of the so-called "2+2" meeting.
"A great deal has changed in this period of time. There are different threats and different kinds of threats, so this is important for us to recognise that this bilateral alliance remains a vital element of our respective national security strategies," Kerry said.
Hagel and Onodera met in Brunei in August and agreed that the two Pacific powers will discuss measures to counter cyber-attacks, as well as renewing the operational arrangements of the alliance to address changing security environments in East Asia.
The meeting comes as Tokyo is looking to reassert itself on the global stage, with Prime Minister Shinzo Abe calling for a more self-confident military stance and as President Barack Obama seeks to pivot towards the rising Pacific region.
In a speech to the Hudson Institute in New York last week, Abe said Japan should no longer be a "weak link" in global security, or for its ally the United States.
Japan is particularly concerned about what it considers China's dangerous behaviour around the Tokyo-controlled Senkaku islands, an archipelago Beijing claims as its own under the name Diaoyus.
There are also fears over North's Korea's nuclear weapons programme after Pyongyang conducted its third and most powerful atomic test to date in February, triggering months of heightened military tensions on the Korean peninsula.
A US think-tank said Wednesday that Pyongyang has clearly restarted an ageing plutonium reactor after analysing new satellite imagery.
On Thursday, Japanese defence chief Onodera said: "We share concerns over various threats from North Korea... and it is a fact that Asian countries have tense relations with China, specifically over marine affairs.
"In this environment, the US presence in East Asia, its alliance with Japan... is playing a very important role" for the peace and security in this region, Onodera said.
One of Washington's primary concerns is the threat from cyber-attacks, which it has said largely emanate from China.
China insists it is also the victim of hacking and points to accusations made by US intelligence leaker Edward Snowden, who said US spies had worked their way into the billion-plus nation's Internet network.
The meeting will also include a review of issues around the planned relocation of a base in urban Okinawa, a thorny subject that has been stalled for years by local opposition.
Tokyo and Washington last year agreed that Japan will meet up to $2.8 billion of the $8.6 billion cost of moving 9,000 US Marines and their families outside Okinawa to Guam and other parts of the world.
While the presence of thousands of US military personnel in Okinawa is a sore point for many islanders, officially pacifist Japan relies on protection provided by them.