TOKYO - The Japanese military could expand its role and missions around the world under new US-Japan defence guidelines expected to be released on Monday that may cause unease in China.
A centerpiece of Japanese Prime Minister Shinzo Abe's US visit this week, the guidelines are part of Abe's wider signal that Japan is ready to take more responsibility for its security as China modernizes its military and flexes its muscles in Asia.
The conservative Japanese leader, who is set to meet US President Barack Obama on Tuesday, will likely want fresh assurances that America will come to Japan's aid if necessary in a clash with China, Japanese politicians and experts said.
The first update of the US-Japan defence cooperation guidelines since 1997, the revisions will reflect the biggest change in Japanese security policy in decades.
The current guidelines focus on the defence of Japan and on "situations in areas surrounding Japan" -- widely interpreted as a possible conflict on the Korean Peninsula -- where Japan's military is relegated to giving US forces "rear-area support."
The new guidelines are likely to expand the geographic scope of cooperation and to include areas such as cybersecurity and counter-terrorism, according to a recent article by Adam Liff, a fellow at the Princeton-Harvard China and the World Program.
They are expected to be unveiled when Secretary of State John Kerry and Defence Secretary Ash Carter see Japanese Foreign Minister Fumio Kishida and Defence Minister Gen Nakatani in New York on Monday as a week of choreographed diplomacy unfolds.
Hours ahead of the announcement, a crowd of about 800, according to protest organisers, gathered outside the Japanese prime minister's office, chanting slogans against the revisions.
Abe meets Obama at the White House on Tuesday and addresses a joint session of Congress on Wednesday, the first Japanese leader to do so.
His speech coincides with pressure from critics to ease concerns that he wants to whitewash Japan's wartime past, while conservative domestic allies feel fresh apologies are unneeded after 70 years of peaceful policies.
A Japanese official said during his US visit Abe would reaffirm Tokyo's commitment to peace and to past expressions of war remorse.
But an opinion poll released on Monday by the Sankei newspaper showed 49.5 per cent of Japanese voters opposed legal changes for the military to fight abroad. Just 36.2 per cent approved.
Despite US assurances, worries persist in Tokyo that one day Washington may not come to Japan's defence, for example in a clash with Beijing over disputed islets in the East China Sea.