Blind Chinese dissident Chen Guangcheng says he wants to leave for the US rather than stay in China, throwing into doubt a deal used to coax him out of the US embassy in Beijing and defuse a standoff that has strained China-US ties.

That standoff appears all the more troublesome for the US, with Chen saying on Thursday that he feared for his and his family's safety if he stayed in China under an agreement that U.S. officials initially said he was happy with.

Chen, a self-taught legal activist, is under Chinese control in a Beijing hospital, having left the embassy on Wednesday. He had taken refuge at the mission for six days after escaping house arrest and left under a diplomatic solution that was meant to assure him that his circumstances in China would be improved.

But Chen told Reuters on Thursday by telephone from hospital, where he was escorted by US officials after leaving the embassy, that he had changed his mind after speaking to his wife who spoke of recent threats made against his family.

"I feel very unsafe. My rights and safety cannot be assured here," he said, adding that his family supported his decision to try to get to the United States.

The activist, citing descriptions from his wife, Yuan Weijing, said his family had been surrounded by Chinese officials who menaced them and filled the family home. Chen, from a village in rural Shandong province, has two children.

"When I was inside the American embassy, I didn't have my family, and so I didn't understand some things. After I was able to meet them, my ideas changed."     

Chen's decision puts more strain on US-China relations at a tense time for both countries. US President Barack Obama will be sensitive to any criticism of the handling of Chen's case in the run-up to a November presidential election and China is struggling to push through its own leadership transition late this year.

US Secretary of State Hillary Clinton found herself in the eye of the diplomatic storm on Thursday, turning up for the opening of annual bilateral talks in Beijing which have been overshadowed but not derailed by the Chen case.

She used the occasion to urge China to protect human rights but made no specific mention of Chen, whom she had spoken to on Wednesday after he left the embassy.

"Of course, as part of our dialogue, the United States raises the importance of human rights and fundamental freedoms," Clinton said. "We believe all governments have to answer our citizens' aspirations for dignity and the rule of law and that no nation can or should deny those rights."     

Despite Chen's change of heart about staying in China, it was unclear if he would be able to travel to the United States.  Having left the embassy and the protection of US authorities, his fate is now in the hands of the Chinese government.

US officials appeared to be no longer with him on Thursday, with the dissident saying he had still not had an opportunity to explain his change of heart to the US side.

"I hope the US will help me leave immediately. I want to go there for medical treatment," Chen said from the hospital, where a pack of camera crews and reporters was waiting outside, kept away from the entrance by a few police. - Reuters