Beijing 'back-sliding on rights'
A top US diplomat has accused China of "back-sliding" on human rights, after two days of dialogue in Beijing.
Assistant Secretary of State Michael Posner said he had raised the subject of the recent crackdown on dissidents and lawyers in China.
But he said that no headway was made when specific cases such as that of detained artist Ai Weiwei were raised.
A Chinese spokesman said that US should not use human rights issues to interfere in China's internal affairs.
Rights groups say the most extensive government crackdown on dissent in years is taking place. Government critics including lawyers, bloggers and activists have been targeted.
The BBC's Michael Bristow, in Beijing, says that some believe China has launched this crackdown because it fears unrest similar to that taking place in the Middle East and North Africa.
Others believe that politicians looking to be promoted in next year's leadership reshuffle are trying to show how tough they are.
Mr Posner said that the two sides had "tough" discussions about issues "deeply" concerning to the highest levels of the US government.
"In recent months we've seen a serious back-sliding on human rights, and a discussion of these negative trends dominated the human rights dialogue," he said.
He said that he had raised cases of several prominent dissidents, such as artist Ai Weiwei - a government critic who has not been seen since his arrest as he tried to board a plane to Hong Kong. The authorities say they are investigating him for "economic crimes".
"On that case, we certainly did not get an answer that satisfies," he said. "There was no sense of comfort from the response or the lack of response."
He also raised cases including that of missing lawyer Gao Zhisheng and Liu Xia, the wife of imprisoned Nobel Peace laureate Liu Xiaobo, who is under house arrest.
The two sides also discussed the issues of Tibet and Xinjiang, both areas where minority groups seeking greater autonomy from China exist.
Mr Posner said the issue could harm bilateral ties.
"Human rights is an essential feature of what we do, and so to the extent that there are serious human rights problems, those problems become an impediment to the relationship," he said.
Chinese foreign ministry spokesman Hong Lei said both sides "had frank and thorough exchanges on issues of mutual concern".
"At the same time we oppose the United States using human rights to interfere in China's internal affairs," he added.