BEIJING - Chinese activist Chen Guangcheng has left the US embassy to seek medical care and join his family, officials said Wednesday, as Beijing demanded a US apology on the eve of key talks between the two powers.

Chen, who riled Chinese authorities by exposing forced abortions and sterilisations under the “one-child” policy, fled house arrest on April 22 and sought refuge in the US embassy where he demanded assurances on his freedom.

Wednesday’s nearly simultaneous announcements from the two countries may not have ended the row, with China demanding an apology for what it called interference in its affairs.

“China is very unhappy over this. The US action is an interference in China’s internal affairs and China cannot accept it,” Chinese foreign ministry spokesman Liu Weimin said, as quoted by the state Xinhua news agency. “China demands that the US apologise and thoroughly investigate this incident, deal with the people who are responsible and ensure these types of incidents do not occur again,” he said.

China also urged the United States to “stop misleading public opinion” over the case of Chen Guangcheng, after Secretary of State Hillary Clinton said Washington remained committed to the activist.

“What the US needs to do is to stop misleading public opinion, and stop hiding their own responsibility and pushing it onto others in this affair,” foreign ministry spokesman Liu Weimin said. Secretary of State Clinton, in Beijing for long-planned talks, spoke by telephone to the 40-year-old activist as he left the US embassy for a hospital where he received treatment and was reunited with his family. “After saying in Chinese how grateful he was that she had mentioned him in the past and supported his case, he said in broken English, ‘I want to kiss you,’” a senior US official said on condition of anonymity.

Chen also told Clinton through an interpreter that he was happy to see his family but made clear he was “prepared for the struggle ahead”, the official said.

Chen was taken to a VIP section of a Beijing hospital in the company of US officials including Ambassador Gary Locke. Around 20 police and security guards, some wearing riot helmets, cornered journalists and ordered them to leave.

US officials said that Chen never requested to go to the United States and became eager to leave the embassy when he learned that his family was waiting at the hospital — including one of his two children he had not met in two years.

“Ambassador Locke said it to him, ‘Are you ready to go?’ And he said, ‘Zou!’, which means ‘Let’s go,’” a second US official said, speaking on condition of anonymity.

Once they started driving toward the hospital, US officials tried to arrange the call to Clinton but initially had difficulty. In their haste, the officials had left their phones at the embassy and Chen’s own mobile telephone did not work. Finally, a lower-level US embassy official handed over a personal phone.

Under the agreement, US officials said that China agreed to let Chen live without harassment with his family and study at a university.

However, China demanded an apology and the agreement could prove controversial in the United States due to concerns over how to verify Chen’s safety.