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

That standoff appears all the more troublesome for the United States, 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 lawyer, 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 U.S. 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 lawyer 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 U.S.-China relations at a tense time for both countries.

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.

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 U.S. authorities, his fate is now in the hands of the Chinese government.

U.S. 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 U.S. side.

"I hope the U.S. will help me leave immediately. I want to go there for medical treatment," Chen said.

U.S.-CHINA DEAL BREAKS DOWN

Washington had hoped the deal it had brokered with Beijing over Chen on Wednesday would defuse the crisis, with Clinton and the U.S. secretary of the treasury in the Chinese capital for the strategic and economic dialogue.

Under the deal, according to U.S. officials, Chen and his family would have been relocated within the country in safety and he would be allowed to pursue his studies.

But Chinese authorities have taken a tough tone, criticizing what they called U.S. meddling and demanding an apology for the way U.S. diplomats handled the case.

Chinese President Hu Jintao made no mention of the Chen case in his remarks to the U.S.-China talks but stressed that the two nations needed trust.

"To build a new type of relationship between China and the United States we need to trust each other," Hu said.

Earlier, Chen directed a personal appeal to Obama in comments aired on CNN: "I would like to say to President Obama, please do everything you can to get our family out."

CHINA DEMANDS APOLOGY

Chen is a self-schooled legal advocate who campaigned against forced abortions under China's 'one-child' policy.

He escaped 19 months of house arrest, during which he and his family faced beatings and threats, on April 22.

U.S. officials had said Chen left the embassy of his own free will because he wanted to be reunited with his wife and children. U.S. officials said that Chen wanted to remain in China and that he never asked for asylum.

Chen's dramatic escape from house arrest last week and his flight to the U.S. embassy have made him a symbol of resistance to China's shackles on dissent, and the deal struck by Beijing and Washington would have kept him an international test case of how tight or lose those restrictions remain.

Now, however, his change of mind throws not only his own future into doubt but also raises questions about the wider U.S.-China relationship.

It could also prove politically costly for President Obama, who has already been accused of being soft on China by Republican presidential candidate Mitt Romney and who could now face further criticism over Chen's case.

What initially appeared to be a foreign policy success for the Obama administration could quickly turn into a liability.