Prominent activist Joshua Wong (L) and Cantopop star Denise Ho (C) testified before a congressional commission about the pro-democracy movement in Hong Kong
Prominent activist Joshua Wong (L) and Cantopop star Denise Ho (C) testified before a congressional commission about the pro-democracy movement in Hong Kong AFP / Olivier Douliery

Beijing Thursday accused Washington of "adding fuel to the fire" of Hong Kong unrest after leaders of the city's pro-democracy movement appealed directly to US lawmakers to exert pressure on China.

Activists from the semi-autonomous city testified before a congressional commission in support of US legislation aimed at defending civil rights in Hong Kong, which has been convulsed by weeks of huge, sometimes violent rallies.

Foreign ministry spokesman Geng Shuang said at a press briefing Thursday that the US should "stop supporting violent radical forces and Hong Kong independence separatists, and stop adding fuel to the fire to the words and deeds that damage the prosperity and stability of the Hong Kong Special Administrative Region."

Geng called for the US to "stop interfering in Hong Kong's affairs in any form."

Millions have taken to the streets of Hong Kong in months of protests, which were initially against a now-dropped bid by its leaders to allow extraditions to the mainland, but broadened into a wider push for democracy.

The hearing on Tuesday examined legislation that would end Hong Kong's special trading status with the US unless the State Department each year certifies that the city's authorities are respecting human rights and rule of law.

Beijing has repeatedly accused "foreign forces" of being behind the pro-democracy protests.

A related bill under consideration would ban the sale of tear gas, rubber bullets and other crowd control equipment to the Hong Kong police after concerns that Western imports abetted their crackdown.

"As I speak, Hong Kong is standing at a critical juncture. The stakes have never been higher," said 22-year-old Joshua Wong, one of the most prominent figures in the largely leaderless movement.

"This is a plea for universal human rights. This is a plea for democracy. This is a plea for the freedom to choose," Cantopop star Denise Ho told the congressional commission.

China summoned Germany's ambassador last week after Wong visited the European power and met with Foreign Minister Heiko Maas -- a meeting Beijing branded "disrespectful".