Stung by U.S. calls for more democracy in Hong Kong (search), China has demanded that the American government "stop interfering" in the territory's internal affairs, the official news agency said Sunday.

Kong Quan (search), a Chinese Foreign Ministry spokesman, was quoted by the Xinhua News Agency as responding to a U.S. State Department spokesman's comment on Hong Kong's political development.

"Hong Kong affairs (are) an internal issue of China, and the Chinese government firmly opposes any foreign government interference in the affairs of Hong Kong in any form," Xinhua said, paraphrasing Kong.

It quoted Kong as saying that "Hong Kong's political structure must develop in a gradual and orderly manner."

Last week, U.S. State Department spokesman Richard Boucher (search) expressed the United States' "strong support for democracy through electoral reform and universal suffrage in Hong Kong," saying that would stimulate the territory's economic development.

"Our belief is in democracy," Boucher said at a briefing in Washington. "The Hong Kong people and the Hong Kong government need to start addressing this issue."

He said the United States wanted to make sure that the people of Hong Kong "get their choice to design their system that's appropriate for them." He added: "We care a lot about the prosperity and stability of Hong Kong."

Pro-democracy protests, some of them quite large, have taken place in Hong Kong since July 1, when 500,000 people marched on the streets against a Beijing-backed national security bill. Activists accuse the territory's Beijing-appointed leader, Tung Chee-hwa, of undermining efforts at self-government.

The refrain is a familiar one for both countries. The U.S. government has long called for more democracy in China, both on the mainland and more recently in Hong Kong. China often insists that such comments are an interference in its domestic policies.

Hong Kong, a former British colony, reverted to Chinese rule in 1997. It is now a special administrative region governed under a doctrine known as "one country, two systems," under which the Chinese government has allowed it to operate semi-independently.

The China-U.S. relationship -- politically, at least -- has been reasonably stable for more than two years, though the economic relationship between the two has grown tense over a U.S. trade deficit and calls from the Bush administration that Beijing float its currency.