President Barack Obama met Chinese Premier Wen Jiabao Tuesday, in the highest-level exchange between the two sides since the US election and an engineered power transfer in China.

Wen and Obama met at the East Asia Summit in Cambodia, as tensions rise over maritime territorial disputes in the region which are nagging the always friction-prone relations between Washington and Beijing.

Both men stuck to familiar talking points in a short photo-op, and ignored questions shouted by reporters about South China Sea showdowns which have centre stage at the summit.

Obama said that, as the world's two largest economies, China and the United States had a "special responsibility" to work together to ensure sustained and balanced growth and to establish "clear rules of the road" on trade.

His comments were a veiled reference to the trade and currency disputes, and issues such as intellectual property piracy and commercial duties over which his, and previous, US administrations have haggled with the Chinese.

Wen congratulated Obama on his re-election this month and sent the regards of the man he referred to as China's "newly-elected" leader, Xi Jinping.

Xi was installed as the head of the ruling Communist Party after a tightly scripted party congress which culminated this month in Beijing, and he is expected to succeed Hu Jintao as national president next March.

Wen told Obama the two sides could work together on business, economic and finance issues -- where they are intertwined -- to tackle "the difficulties we have and resolve the differences and disagreements between us".

Washington has become increasingly frustrated with Beijing over its refusal to back stronger measures against the Syrian regime, while trade disputes fester between the two nations.

Obama took a tough line on some aspects of Chinese trade and economic policy during his re-election campaign, covering his political flank as Republican candidate Mitt Romney flailed away at Beijing.

The United States has called on China to manage territorial disputes in the South China Sea with a regional code of conduct that would ease tensions, but Beijing wants to discuss disputes only with individual claimant nations.

China frees jailed opponent of Bo Xilai
Beijing (AFP) Nov 20, 2012 - A Chinese official sentenced without trial to hard labour for opposing the Maoist revival policies of disgraced politician Bo Xilai has been freed and is seeking compensation, his lawyer said Tuesday.

Ren Jianyu, 25, was released from a re-education through labour camp in Chongqing, the southwestern city Bo used to head, after serving 15 months for attacking his "sing red" campaign, lawyer Pu Zhiqiang told AFP.

Bo is at the centre of the biggest political scandal in China in years, which saw his wife given a suspended death sentence in August for murdering British businessman Neil Heywood.

Bo was kicked out of the ruling Communist Party late last month and is in custody awaiting trial for corruption and abuse of power.

Before the scandal erupted, he had been tipped for promotion to the top ranks of the party at its once-a-decade leadership transition that saw President Hu Jintao hand the top party post to Vice President Xi Jinping last week.

"Ren Jianyu was released from the labour camp on Monday," Pu told AFP by telephone. "The authorities did not give a reason why they released him, but we believe he has been unjustly jailed."

Ren was a local Chongqing official when he was arrested for reposting numerous microblog comments that criticised Bo's "sing red" movement and equated it to the disastrous Maoist "Cultural Revolution" that brought chaos to China from 1966-1976.

Police in Chongqing had initially tried to convict Ren of subversion using a T-shirt of his scrawled with "Give me liberty, or give me death" as evidence.

But Chongqing prosecutors threw out the case and Pu was instead sentenced without trial by police to two years of labour in August 2011.

In China, police can sentence petty criminals to labour camps without trial, a practice widely criticised by rights groups, as well as the United Nations.

Last month, Ren's father sued the Chongqing government, demanding his son be released and reinstated to his job, and given a public apology, Pu said. A Chongqing intermediate court is due to rule on the case Tuesday, he added.

Ren's trial and fate have been widely followed on China's Twitter-like microblog Sina Weibo. Since Bo's downfall, state media have also reported Ren's attempts to seek compensation and restore his reputation.