The White House has said it welcomed the departure of blind dissident Chen Guangcheng from China, ending a tense diplomatic drama with Beijing.
A plane carrying the Chinese activist and his family is now en route to America.
"We note that Mr Chen and his wife and two sons are on their way to the United States," a national security advisor, Ben Rhodes, said.
"We welcome this development and the fact that he will be able to pursue a course of study here in the US."
Two American diplomats are accompanying Mr Chen on the United Airlines flight, Sky News understands, and it is scheduled to arrive at Newark, New Jersey, this evening (local time).
Earlier, the 40-year-old activist told Sky News he was at Beijing airport after receiving his passport from a US diplomat.
He had been in hospital since leaving the US embassy in the Chinese capital, where he had sought refuge for several days.
Mr Chen told Sky News Asia correspondent Holly Williams his family had received their passports and they would be flying from Beijing.
Asked how he felt, he said he was "filled with thousands of mixed emotions".
"If I tried to express how I feel right now, I couldn't find the words," he told Williams.
Mr Chen also revealed he was told by people at the hospital that he would be able to leave, but he has had no contact with government officials.
He added that he and his wife, son and daughter were given their passports by an American diplomat.
The blind activist admitted he was very worried about his family still in China - some of them remain under home detention.
Mr Chen also said he did not know what to expect in the US, where he plans to study law, and when asked if he would return to China, he answered: "Yes, yes, yes. I definitely will. It's my right."
China's state news agency Xinhua said Mr Chen had applied to study in the United States "via normal channels in line with the law", but failed to mention that the activist had left the country.
The US government has struggled to contain a diplomatic row over Mr Chen, who escaped from house arrest in April and sought refuge at the US embassy.
Earlier this month, American diplomats escorted him to a Beijing hospital after the Chinese authorities promised he and his family would be treated "humanely".
Hours later, he changed his mind about staying in China and claimed his family was in grave danger.
He told Sky News by phone that government officials armed with sticks had threatened his family members, installed seven surveillance video cameras in his home and were planning to put an electric fence around his house.
The Chinese government has been angered by what it views as unwanted American interference.
An editorial in the Beijing Daily newspaper described Mr Chen as "a tool and a pawn from American politicians to blacken China".
Mr Chen came to prominence in 2005 after exposing the plight of thousands of people in his home province of Shandong who had been forced to undergo surgical sterilisation and abortions by government officials.
As a result of his activism, he was sentenced to four years in prison for "damaging property and organising a mob to disturb traffic".
During his trial, Mr Chen's lawyers were denied access to the courtroom. His conviction caused an international outcry.
After his release in 2010, Mr Chen was placed under "soft detention" at his home.
Journalists and diplomats who attempted to visit the legal activist were turned away.
When the actor Christian Bale tried to meet with him last year, he was barred from entry and roughed up by security guards.