Joshua Wong has been barred from standing in upcoming local elections in Hong Kong, a decision Beijing said it approved of

Beijing expressed "approval and support" Wednesday for the disqualification of Hong Kong democracy activist Joshua Wong from upcoming local elections, after months of protests in the semi-autonomous city.

Wong, one of the most prominent figures in the otherwise leaderless movement, accused the Hong Kong government of "political screening" after an election officer ruled his nomination for the November poll invalid on Tuesday.

But a spokesman for China's top policy body on Hong Kong affairs said Wednesday that Wong had over many years "proclaimed the viewpoints of so-called 'self-determination' and 'Hong Kong independence' and publicly denied that Hong Kong is a part of China".

During recent protests Wong "repeatedly grovelled to foreign powers for sympathy and begged for interference", Yang Guang, of the Hong Kong and Macau Affairs Office, said on the body's website Wednesday.

He "is one of the chief culprits challenging the red-line principle of 'one country, two systems'", Yang said.

"We express approval and support of this decision."

The 23-year-old rose to prominence as the poster child of the huge pro-democracy "Umbrella Movement" of 2014 that failed to win any concessions from Beijing, and served time in jail for his role in those protests.

Wong was the only candidate barred from standing in an election for district councils, which tackle regional issues. The election is the first to be held since the current anti-government protests started.

Wong accused the Hong Kong government on Tuesday of accepting "a political mission handed down from Beijing" by banning him from the polls.

The Hong Kong election officer wrote in her reasoning that Wong´s concept of self-determination does not rule out the independence of Hong Kong as an option, which she deemed inconsistent with the Basic Law, the city´s mini-constitution.

Wong and his party, Demosisto, have denied supporting independence for the city.

They say they advocate self-determination and a referendum for Hong Kong people to decide how they want to be governed.

Last year, Agnes Chow, another young pro-democracy leader from Wong's party, was barred from standing in by-elections because her party advocates self-determination for Hong Kong.