US Secretary of State Hillary Clinton voiced alarm over Beijing's treatment of Tibetans and a blind rights activist as tensions between the superpowers threatened to intrude on Pacific Rim talks.
In Honolulu for an Asia-Pacific summit, Clinton said the United States welcomed a "thriving China" but pressed the growing Asian power on both human rights and its economic policies.
"When we see reports of lawyers, artists and others who are detained or 'disappeared,' the United States speaks up both publicly and privately," Clinton said in a speech at the East-West Center think-tank shortly before a scheduled meeting with Chinese Foreign Minister Yang Jiechi.
China had already struck a discordant note ahead of the summit, saying earlier this week that US goals for the meeting in Hawaii -- which include getting the ball rolling on a regional free-trade pact -- were "too ambitious".
As Chinese President Hu Jintao arrived in Honolulu for the summit, Clinton said the US was "alarmed by recent incidents in Tibet of young people lighting themselves on fire in desperate acts of protest, as well as the continued house arrest of the Chinese lawyer Chen Guangcheng."
"We continue to call on China to embrace a different path."
Clinton is the highest-level US official to raise concern publicly about Tibet and Chen amid growing alarm in recent months.
Ethnic Tibetan areas of China have seen a wave of self-immolations by Buddhist monks and nuns in protest at what they see as Beijing's stifling rule. Rights groups say that at least five monks and two nuns have died.
Chen, a self-trained lawyer who has been blind since childhood, spent four years in prison after documenting late-term abortions and forced sterilizations under Beijing's one-child policy.
He was released last year, but rights campaigners say he and his wife were severely beaten earlier this year in apparent retaliation for the release of a video smuggled out of their home in which Chen railed against his house arrest.
Campaigners say paid thugs continue to attack anyone who tries to reach Chen in his village in eastern China.
Clinton also raised concerns about China's economic policies, including its alleged preference for state-run firms in procurement and the value of its currency, which critics say is kept artificially low to boost exports.
She noted that US firms want more market access in China, while Chinese firms want to be able to buy more high-tech products from the United States, invest more here, and see China treated like a true market economy.
"We can work together on these objectives -- but China needs to take steps to reform," Clinton said.
US Treasury Secretary Timothy Geithner said Asian economies, and "China, in particular," must free up their currencies.
He also said Asian economies must do more to stimulate domestic growth to help protect the global economic recovery from being imperiled by the European debt crisis.
The United States hopes to use its chairmanship of the 21-member Asia-Pacific Economic Cooperation (APEC) forum to set the terms of a free trade deal that could breathe life into moribund global trade liberalization talks.
Leaders will be watching closely in Honolulu to see if Prime Minister Yoshihiko Noda brings Japan into talks on the Trans-Pacific Partnership (TPP), a step that would leave China conspicuously on the outside of the US-brokered pact.
On the eve of the summit, China's assistant foreign minister Wu Hailong said developing economies in the fast-growing region had already "expressed their difficulties and concerns" at US targets for lower tariffs on environmental products and for reductions in energy intensity.