Beijing on Wednesday warned the United States against building military alliances in the region, where a series of maritime disputes have fueled tensions, as China and Russia cemented close bilateral ties with joint naval exercises and a giant multibillion-dollar energy deal.
A day after Chinese President Xi Jinping and his Russian counterpart Vladimir Putin launched naval exercises in the East China Sea amid a territorial dispute with Japan, Xi appeared to warn Washington off any military involvement in the region.
"To beef up an entrenched or military alliance targeted at a third party is not conducive to maintaining common security," Xi said Wednesday to delegates to the Conference on Interaction and Confidence Building Measures in Asia (CICA), a regional group that includes Russia and Iran but excludes the United States.
Also on Wednesday, Beijing and Moscow inked a U.S. $400 billion-dollar gas deal that could supply China's energy-hungry economy for the next three decades.
The 30-year deal was clinched after a decade of talks, underscoring a turn to the east by Moscow at a moment when its geopolitical assertiveness, particularly the takeover of Crimea, has seen it heavily attacked by the West.
Xi's comments echoed an editorial published by the official Xinhua news agency on Tuesday.
"Players from other parts of the world need to play a constructive role," the article said. "They should refrain from starting fires and stoking flames."
Since coming to power in November 2012, Xi has presided over an increasingly assertive foreign policy that has seen Beijing lay fresh claim to a number of disputed, resource-rich island chains.
He has also continued a policy of cultivating an ever-closer relationship with Moscow, analysts said.
Putin's visit to China culminated on Wednesday in the signing of the gas supply contract between the China National Petroleum Corp (CNPC) and Russia's Gazprom.
The gas, to be delivered from 2018, will be transported along a new pipeline linking Siberian gas fields to China's main consumption centers near its coast, officials said.
Speaking at CICA, Xi also mooted the idea of a regional security code.
Chinese political commentator Lin Baohua said a close partnership between Beijing and Moscow has underpinned much of Xi's regional muscle-flexing.
"Xi Jinping continued to implement this ... traitor's treaty that the two sides will never be enemies, and his first trip overseas as president was to Moscow," Lin wrote in a recent commentary aired by RFA's Mandarin Service.
"China definitely won't be fighting for every inch of territory with Russia; if it must fight, it will tussle with Japan, Vietnam or the Philippines," he said.
But he said Russia's backing in central Asia also had an effect on Chinese policies in the troubled northwestern region of Xinjiang, home to the mostly Muslim Uyghur ethnic group.
“With Putin's backing, Xi can continue to shout fiercely and take a zero tolerance attitude to the [so-called] three evil forces of terrorism, separatism and extremism," Lin said.
Xi told CICA delegates that the group had a broad consensus over security cooperation.
"We all agree that Asian countries should cooperate in fighting terrorism, drug trafficking, and cross-border organized crime," he said. "We should safeguard food, energy, and information security."
However, Southeast Asian leaders have said they are also seriously concerned over rising territorial tensions in the region.
Japan, which controls the disputed Diaoyu, or Senkaku, Islands in the East China Sea, was present at the CICA summit as an observer, while the Philippines, which disputes a separate maritime area with Beijing, wasn't represented.
Vietnam, which was swept last week by anti-Chinese riots that left at least two dead and dozens of factories destroyed or looted, is a full member of the group, which China hopes to build into a high-profile security summit.
Chinese censors cut off a live media feed of proceedings before the summit had ended, relaying only Xi's speech and remarks by a Turkish delegate.
The live broadcast controlled by state broadcaster CCTV stopped abruptly as Vietnamese Vice President Nguyen Thi Doan shook hands with Xi, prompting jokes that current tensions with Vietnam would make such a scene worth censoring.
After the summit ended, Vietnamese Prime Minister Ngyuen Tan Dung said following a meeting with Philippine President Benigno Aquino in Manila that China's dispatch of an oil rig to the disputed Paracel Island chain had "seriously threatened peace."
The deployment of the rig sparked waves of furious protests across Vietnam that later turned to riots last week, prompting the evacuation of Chinese expatriate workers and calls for compensation from investors.
Meanwhile, authorities in Shanghai moved to detain dozens of critics of the ruling Chinese Communist Party amid a heavy police presence in the city, Shanghai-based rights activists said.
“There were so many [police], it was unbelievable," Yu Zhonghuan, husband of Shanghai-based activist Shi Ping told RFA. "Dozens of people here have been placed under criminal detention because of the CICA summit."
"Xi Jinping [was] staying at the Xijiao Hotel, and a bunch of petitioners went to try to call on Xi Jinping to pay attention to their rights," said Yu, whose wife was was among those detained.
“They were all detained on the same day, while dozens more are still in hiding elsewhere," he said, adding that he had narrowly missed detention by leaving the scene ahead of his wife.
He said some activists had been taken on a forced "vacation" by state security police, while others were under 24-hour surveillance by authorities.
Shanghai rights activist and petitioner Shen Peilan said she was taken away from her home ahead of the summit and released after it ended on Wednesday.
“They didn't want anything going wrong during the CICA summit, and they want to guarantee security," Shen said after her release on Wednesday.
"I asked them what I could be doing wrong sitting at home, and the state security police told me I was making lots of phone calls," she said.
“They shouldn't be taking this out on us petitioners," Shen said, referring to ordinary people who pursue complaints against the Chinese Communist Party, often for years or decades.
“I said to them, is it a crime to make a phone call now?"
Reported by Xin Lin for RFA's Mandarin Service, and by Lin Jing for the Cantonese Service. Translated and written in English by Luisetta Mudie.