Dissident Chinese artist and activist Ai Weiwei is taking heart from recent public protests in China over the authorities' strict Covid-19 policy - but admits he does not see them bringing about any significant political change.

"I don't think that's possible," he told The Associated Press in an interview at his home in Portugal.

The recent unrest in several Chinese cities that has questioned Beijing's authority - going so far as to demand President Xi Jinping's resignation in what have been the boldest protests in decades - is "a big deal," Ai acknowledges, but he believes it is unlikely to go any further.

Challenges to Chinese Communist Party rule are routinely snuffed out with whatever degree of brutality is required. Ai points, for example, to how Beijing cracked down on Hong Kong's pro-democracy movement two years ago.

In his view, some "realistic thinking" is required.

"Everything is about control ... to guarantee the whole nation will follow (Xi's) direction," the 65-year-old said in the interview at his country house about 60 miles east of Lisbon.

His 2020 documentary Coronation, about the lockdown in Wuhan, China, during the Covid-19 outbreak, illustrated the country's ruthlessly efficient and brutal official response to the pandemic.

The Chinese government's "zero-Covid" policy included harsh measures that, according to Ai, kept some people confined to their apartments for 100 straight days.

Three gruelling years of lockdowns and other severe restrictions, along with Mr Xi's scrapping of civil liberties, built up "tremendous pressure" in Chinese society, Ai says.

The protests were triggered on November 25, after at least 10 people died in a fire in an apartment building in China's north-west.

Though officials denied suggestions that firefighters or victims were blocked by locked doors or other anti-virus controls, the disaster became a focus for public frustration.

Ai sees an inevitability in the public's exasperation, and is cheered by the questions it has raised.

"Of course, they start questioning the leadership and the social structure, the political structure," he said.

Beijing has in recent weeks relaxed some measures, and on Wednesday announced a series of steps rolling back some of its harshest pandemic restrictions in an apparent nod to public frustration.

Ai warns, however, that the relatively small protests, some of which have involved just individuals or neighbourhoods, should not be overstated in a country with a population of 1.4 billion people.

And he recalls that the Chinese Communist Party has some 100 million members, all loyal to the regime.

Though "not at all" hopeful of meaningful change in China in the foreseeable future, Ai sees encouraging signs in the protests. They may represent, he says, baby steps towards a more distant goal.

"What (is) clear is the new generation of young people from China - students or young workers - they start to be more clear about what kind of government China is and maybe also (demand) political change," he said. "But that would take a long time."

He is also gloomy about the muted international response to the clamour for change by some Chinese people, seeing foreign governments as more interested in economic relations with Beijing than human rights issues.

Long an outspoken critic of the Chinese government, Ai was detained by the authorities for almost three months in 2011. He has lived in exile since 2015, most recently in the countryside of southern Portugal where he says he has now settled.

On Saturday, in a show of support for the Chinese protesters, Ai will appear at Speakers' Corner in London's Hyde Park. He will give out blank sheets of paper, which have been a symbol of opposition to Beijing's censorship, signed with invisible ink.