HONG KONG — The new U.S. envoy to Hong Kong Clifford Hart insisted on Tuesday that Washington would not be silenced by China in calling for democracy in the global financial hub, vowing to continue speaking out for core rights and freedoms.

U.S. Consul-General Hart's first public speech in the former British colony came amid rising political and diplomatic tensions that have included formal warnings from China that Western nations must not meddle in the city's politics.

Hart has already been targeted, with Beijing's top Hong Kong-based Foreign Ministry representative, Song Zhe, warning him against interference while Communist Party-backed newspapers rail against his "subversive" activities.

"The U.S. position on genuine universal suffrage is unchanged. . . . We'll continue to speak out on it," said the career diplomat, who has served in China, Russia, Iraq, and in the Pentagon. "There is no mystery to it, there is no hidden agenda to it whatsoever."

Hong Kong returned to China in 1997 with wide-ranging autonomy, an independent judiciary and relatively free press under the formula of "one country, two systems."

Hart used his address to the American Chamber of Commerce — a reflection of a strong multinational business presence in Hong Kong — to outline Washington's hopes for the political reform promised under that model.

Hong Kong's special status had been "indispensable to its stability, prosperity and growth", he said — a status that includes an undated promise from Beijing to introduce universal suffrage.

"We believe that an open society, with the highest possible degree of autonomy and governed by the rule of law, is essential to maintain Hong Kong's stability and prosperity," he said.

Hong Kong elects its next leader in 2017 in what will be the most far-reaching version of democracy on Chinese soil — but precise arrangements have yet to be hammered out.

Beijing's top representative in Hong Kong has ruled out open nominations for candidates, meaning he or she will be chosen by a committee stacked with Beijing loyalists.

When asked when he drew the line between routine diplomatic work and interference, Hart said the United States respected the right of Hong Kong and Chinese people to conduct their own affairs but "we reserve our option to comment on things we consider important because they directly affect U.S. interests or touch on core values of the U.S."