Barack Obama leaves Cambodia today at the end of a three-day, three-country tour of Asia - his first foreign trip since being re-elected as US President.
After the symbolism of his historic visit to Burma, Mr Obama's 24 hours in Cambodia had a geo-political focus when he was a guest at the summit of the Association of Southeast Asian nations (Asean).
The issues discussed included free trade pacts, human rights records in the region and also the ongoing series of disputes over territory in the East and South China Seas.
China claims a huge U-shaped stretch of water including areas also claimed by Japan, the Philippines, Vietnam, Malaysia and Brunei.
As well as attending a gala dinner at Phnom Penh's Diamond Island Convention Centre, Mr Obama has held one-on-one meetings with a number of the region's key players.
He met the Japanese Prime Minister Yoshishiko Noda and had what could have been a tricky meeting with the outgoing Chinese Premier Wen Jiabao.
The two men posed for a short photo-call and ignored reporters' questions about the territorial disputes.
Mr Obama, who was congratulated by Mr Wen on his re-election, said the world's two largest economies had a "special responsibility" to work together to ensure sustained and balanced growth.
In a reference to China's habit of undercutting American and other Western manufacturers which some believe involves "currency manipulation", Mr Obama said there was a need to establish "clear rules of the road" on trade.
Mr Wen, who is essentially a lame duck, given that he leaves office in March, said the two countries would strive to tackle "the difficulties we have and resolve the differences and disagreements between us".
The territorial dispute between Japan, a close ally of the US, and China over a series of islands in the East China Sea has caused significant tension and a rise in nationalistic sentiment in both countries.
Western diplomats have warned that the increased naval presence from both countries in the contested region could spark a military accident which, in turn, could escalate the dispute.
The last time the Asean nations met in July, the region's territorial disputes were not discussed.
China was accused of pressurising the host country, Cambodia, to take the issue off the agenda.
President Obama is pivoting America's geo-political focus towards Asia in an attempt to counter China's increasing dominance across the region.