Media playback is unsupported on your device Media caption Mr Chen was picked up from a hospital and taken to Beijing airport

Chinese activist Chen Guangcheng - who was at the centre of a diplomatic crisis with Washington - is on his way to the United States.

The blind activist and his family boarded a flight to Newark, near New York, after being taken from a Beijing hospital to the capital's airport.

Mr Chen recently spent six days in the US embassy in Beijing after escaping house arrest in north-east China.

He has been offered a fellowship at New York University.

A White House spokesman welcomed news of Mr Chen's departure.

Mr Chen, a self-taught lawyer who campaigned against forced abortions under China's one-child policy, was jailed for four years in 2006 for disrupting traffic and damaging property, and placed under house arrest after his release in 2010.

'Leave of absence'

Earlier on Saturday, Mr Chen was picked up from the hospital where he was being treated for a foot injury and taken to Beijing airport, along with his wife and two children.

Analysis The case of Chen Guangcheng triggered an extraordinary diplomatic dispute. But with the blind activist now on his way to the US, both Beijing and Washington will want to put this affair behind them. Mr Chen's low-key departure will have been designed to spare Beijing further embarrassment over the case. In the short term, both China and the US may see this episode as a sign of a maturity in their relationship, as the case of one man did not escalate into a bigger crisis. But in the long term, it highlights profound differences between a superpower and a rising power on how they view the world. It was not just about an individual, but about an issue - human rights in China. Mr Chen said this week that he fears his relatives and friends would face more reprisals if he left China.

At the airport they were handed passports and allowed to leave. They boarded flight UA88 to Newark, New Jersey, which departed at 17:50 (09:50 GMT), more than two hours late.

"Thousands of thoughts are surging to my mind," Mr Chen told the Associated Press news agency from the terminal.

Referring to his supporters, he said: "I am requesting a leave of absence, and I hope that they will understand."

The state-run Xinhua news agency said Mr Chen had applied to study abroad "via normal channels".

In a statement sent to Reuters news agency, the foreign ministry said: "Chen Guangcheng is a Chinese citizen. China's relevant departments have handled the procedures for exiting the country in accordance with the law."

Jerome Cohen, co-director of the US-Asia Law Institute at the New York University School of Law, said he was "very happy to receive the news that Chen Guangcheng" was on his way to the US.

"I look forward to welcoming him and his family tonight and to working with him on his course of study," he added.

Bob Fu, president of the US activist group China Aid and a key supporter of Mr Chen, told the BBC that the dissident was planning to stay in New York for two to three years.

"Of course he wants to spend some time to rest after seven years of brutal treatments at the hands of the Chinese local authorities," Mr Fu said.

'Reprisals'

With the activist on his way, both China and the US will want to put this extraordinary diplomatic dispute behind them, says the BBC's Martin Patience in Beijing.

Last month Mr Chen fled from house arrest in Shandong province.

Chen Guangcheng timeline 27 April: It emerges the blind activist has escaped house arrest in Shandong province and is in a "safe location" in Beijing

It emerges the blind activist has escaped house arrest in Shandong province and is in a "safe location" in Beijing 28 April: Within 24 hours fellow activists say he is at the US embassy

Within 24 hours fellow activists say he is at the US embassy 2 May: Mr Chen leaves the embassy for hospital ahead of a visit by US Secretary of State Hillary Clinton to China for talks

Mr Chen leaves the embassy for hospital ahead of a visit by US Secretary of State Hillary Clinton to China for talks 4 May: He phones a US Congressional hearing to plead for help leaving China. He is offered a fellowship at a US university

He phones a US Congressional hearing to plead for help leaving China. He is offered a fellowship at a US university 16 May: In a second call to Congress he accuses local authorities of harassing his family

In a second call to Congress he accuses local authorities of harassing his family 19 May: Chen and his family leave China

According to media accounts, the blind activist climbed over the wall of the property with the help of his wife late at night.

When he landed on the other side he broke his foot. He is then said to have felt his way in the dark, stumbling and falling, to a nearby village when a friend took him into his home.

He was then driven hundreds of kilometres away to the American embassy. He took refuge there during a visit by US Secretary of State Hillary Clinton, who was in Beijing for high-level talks.

On 2 May, after six days at the embassy, he agreed to leave the compound, initially saying he wanted to stay in China.

He was taken to hospital for treatment. During his stay there he called the US Congress twice.

On 3 May he pleaded for help to leave China with his family, saying he feared for his safety, and on 16 May he called again, accusing Shandong authorities of harassing his family.

Mr Chen was offered a place to study law at New York University after Beijing said he would be allowed to apply to study abroad.

The US has said visas for Mr Chen and his family are ready.

However the activist has repeatedly warned that his friends and relatives could face reprisals once he has left.