Barack Obama set foot in Asia for the first time as US president on Friday, arriving in Japan to launch a four-nation tour designed to shore up US power in a region increasingly dominated by rising giant China.
Air Force One landed in a chill Tokyo drizzle ahead of Obama's talks with Prime Minister Yukio Hatoyama, who is vowing after ending half a century of conservative rule that Japan will be more assertive in its US alliance.
Obama leaves a clutch of domestic crises behind as he seeks to counter charges that US influence has frayed in Asia, with Washington distracted by its deep economic slump and the sapping wars in Iraq and Afghanistan.
Just over a year since capturing the White House, Obama will meet many regional leaders for the first time at the Asia Pacific Economic Cooperation (APEC) summit in Singapore.
He will also become the first US president to sit down with all 10 leaders of the Association of Southeast Asian Nations, including US foe Myanmar.
Obama will then head to China in the three-day centrepiece of his tour, with top global security issues and trade and currency differences on the agenda, and wrap up his trip in South Korea.
In Japan, where a new government took power two months ago, both sides will seek to smooth over a row on US bases and stress shared goals on climate change, the Afghanistan war and for a nuclear-weapons-free world.