In the most tender moments of "Human Flow," Ai Weiwei's epic documentary on the worldwide migrant crisis, he is seen hugging, cooking with and cutting the hair of refugees.

An ordinary filmmaker might be accused of getting too close to his subject but, as far as the Chinese dissident and internationally renowned artist is concerned, he is the subject.

"When I look at people being pushed away from their home because of war, because of all kinds of problems, because of environmental problems, famine, I don't just have sympathy for them," he tells AFP.

"I do feel that they are part of me and I am part of them, even with very different social status."

Ai, 60, opened up about his own displacement as a child in a recent interview with AFP, his trademark beard cut short and his blue and white sneakers color-coded to match his casual shirt and loose-fitting slacks.

The venue, a plush office in Beverly Hills, could have been a million miles away from the labor camps where he grew up, a refugee in his own country as the son of dissident poet Ai Qing.

Shortly after Ai's birth, the People's Republic of China was founded, and Ai senior found himself at odds with the authorities, accused of being a "rightist" during Mao's anti-intellectual Cultural Revolution.

The family was exiled for 20 years, first near the Russian border and then in the northwestern province of Xinjiang, where his father was forced into hard labor, including cleaning communal toilets.

"He was doing that for years and our family were beaten and insulted, seen as the most dangerous species threatening the revolution," Ai remembers.

- Desperation -

The family was allowed to return to Beijing after Mao's death in 1976 and Ai moved to the United States for 12 years.

After coming of age as an artist in early 1990s New York, he returned to Beijing, becoming an increasingly bold provocateur, chafing against the Chinese authorities.

As his global reputation grew, he was watched relentlessly by the authorities, beaten by police and put under house arrest.

Thrown in jail without credible charges for 81 days in 2011, he had his passport confiscated for four years.

Ai -- whose lawyers in the case have both been jailed -- tells AFP that when he looks back on his treatment, it is frustration he feels rather than anger.

"I have so many friends who are detained without trial. Nobody knows where they are, no lawyer can see them. It's very common in China, even today," he says.

Now a refugee in his own right in his new home in Berlin, the father of one young son only feels comfortable returning to China alone.

"Human Flow," his powerful expression of solidarity with refugees around the world, demonstrates the staggering scale of the refugee crisis and its profoundly personal human impact.

Captured over a year in 23 countries, it follows a chain of human stories that stretches from Bangladesh and Afghanistan to Europe, Kenya and the US-Mexico border.

Ai travels from teeming refugee camps to barbed-wire borders, witnessing refugees' desperation and disillusionment as well as hope and courage.

- 'Intimate approach' -

"I'm so far away from their culture, their religion or whatever the background. But with a human being, you look at him, you know what kind of person he is," says Ai.

"I have this natural understanding about human beings. So I try to grab them with this kind of approach, a very intimate approach. They can touch me, cut my hair. I can cut their hair. I can cook in their camp."

"Human Flow" is far from Ai's first work on the refugee crisis. Just last week he scattered over 300 outdoor works across New York as part of a new illustration of his empathy for refugees worldwide.

Ai dismisses a common criticism that his work has little artistic merit and that he is more of a campaigner, telling AFP "a good artist should be an activist and a good activist should have the quality of an artist."

"Human Flow," which premiered at the Venice film festival last month and opens in Los Angeles on October 20, ends on the US-Mexico border that President Donald Trump has promised to turn into "a beautiful wall."

Ai said the administration had brought "shame on the fundamental beliefs of what this nation is made of," killing the US reputation for "energy, imagination, creativity."

The artist has given up hope of returning home with his family but hopes his film will contribute to people seeing refugees as human beings.

"I believe anybody sitting in the theater would come out with their own judgment," he said.

"They look at those children and think about their own children, look at the elderly people there, think about their own parents."

-AFP