On his way to the Chaoyang Hospital accompanied by the U.S. ambassador. Chen called his lawyer, Li Jinsong, who said Chen told him: "'I'm free. I've received clear assurances."'
Though Li said Chen did not elaborate, the activist had been seeking guarantees of his and his family's safety.
"Chen Guangcheng has arrived at a medical facility in Beijing where he will receive medical treatment and be reunited with his family," said a senior U.S. official, who spoke on condition of anonymity due to the sensitivity of the issue. The official did not give additional details on Chen's whereabouts or condition.
The Chinese government's news service, Xinhua, reported that Chen left the U.S. Embassy "of his own volition" after staying there for six days.
Xinhua, in the brief English-language report, said that the Chinese Foreign Ministry has also demanded the U.S. "apologize for a Chinese citizen's entering" the embassy.
The statements were the first official comments by either government on Chen's case since his supporters said last Friday that he had escaped 20 months of house arrest by local authorities at his village in Shandong province, and traveled to Beijing where he went into U.S. government protection.
His flight into U.S. hands gave Washington and Beijing a delicate human rights crisis at a time when they are trying to shore up shaky relations to deal with the unsteady global economy and trouble-spots from Iran and Syria to North Korea.
Clinton's arrival earlier Wednesday upped the stakes for a resolution. Annual talks led by Clinton and Treasury Secretary Timothy Geithner and their Chinese counterparts open Thursday and are supposed to focus on trade tensions and security issues.