Chinese dissident Chen Guangcheng says he has been unable to meet US officials to discuss his desire to leave the country.

The blind activist, in hospital in Beijing, told the BBC he believed Chinese officials were preventing US envoys from visiting him on Thursday.

After he escaped house arrest last week, Mr Chen spent six days in the US embassy before emerging on Wednesday.

The issue continues to overshadow key talks between the US and China.

US Secretary of State Hillary Clinton is in Beijing to attend talks focusing on North Korea and Syria.

As the talks opened, Mrs Clinton did not mention Mr Chen by name but addressed the topic of human rights.
'Threats to family'

Over the past two days there have been a number of reports, sometimes contradictory, about exactly why Mr Chen left the embassy and what information he had been given.

The US ambassador to China, Gary Locke, on Thursday rejected the suggestion that Mr Chen had been pressured into leaving.

"I can tell you unequivocally that he was never pressured to leave. He was excited and eager about leaving," he said.

However, US state department spokeswoman Victoria Nuland acknowledged to reporters that "they as a family have had a change of heart about whether they want to stay in China".

She added: "We need to consult with them further, get a better sense of what they want to do, and together consider their options."

The BBC's Jonny Dymond in Washington says that, beyond this, the US is being fairly tight-lipped about what its officials are now doing.

He says the impression is that efforts are going on behind the scenes to ascertain Mr Chen's wishes and where to go from here, all the time balancing that against the diplomatic difficulty of having Hillary Clinton and Treasury Secretary Timothy Geithner in Beijing for bilateral talks.

Mr Chen told the BBC by telephone from his hospital bed, in an interview conducted in Chinese, that since he left he has been made aware of threats issued to his wife and family while he was in the embassy.

"She told me our house has been installed with seven CCTV cameras inside the courtyard. There are people in and outside of our house and on the roof... They just eat and stay in our house, and they plan to build up electric wires around my house," he told the BBC.

Although he initially said he wanted to stay in China, he changed his mind because he believed China had reneged on an agreement to guarantee his safety.

There is no official confirmation about the nature of any such agreement, but media reports from the US suggest that Mr Chen had been promised safety in a university town elsewhere in China.

Mr Chen also said that US officials had been to the hospital where he is currently receiving treatment, but he had not seen them. He believes Chinese foreign ministry officials are not letting them in. There is a considerable police presence at the hospital.

"Yesterday afternoon I thought they (the US officials) left. I looked for them, but couldn't find them... Today I got to know that they were prevented from coming in, not that they are not coming in," Mr Chen said.

A Chinese foreign ministry spokesman said he had "no information" on Mr Chen's request to leave China.
'Universal rights'

Mrs Clinton has previously expressed her support for Mr Chen, who has been held under house arrest for almost two years.

As the bilateral talks opened, she addressed the topic of human rights.

"The United States believes that no state can legitimately deny the universal rights that belong to every human being - or punish those who exercise them," the top US diplomat said.

President Hu Jintao, also speaking at the start of the talks, said it was not possible for China and the US to see "eye to eye on every issue".

Chinese officials on Wednesday accused the US of interference in China's domestic affairs and demanded an apology for housing Mr Chen at the US embassy.

Mr Chen had been at the embassy for almost a week after escaping from house arrest in his home village in the eastern province of Shandong.

He had planned his escape from house arrest for months. On 27 April, he scaled the wall the authorities had built around his house and was then driven hundreds of miles to Beijing.

Several people involved in Mr Chen's escape have been detained or have disappeared in recent days.

The activist has spent seven years in prison or under house arrest after he exposed human rights abuses, including the way thousands of women were forced to have abortions under China's "one-child-policy".