WASHINGTON - The world is watching how China deals with Hong Kong and its commitments to preserve freedoms there amid continuing tensions over pro-democracy protests, the United States' top diplomat for East Asia said Wednesday.

Daniel Russel told a Senate panel the U.S. supports the right of citizens of the semiautonomous Chinese city to a free election for its chief executive in 2017.

Russel denied Chinese allegations that the United States had helped foment the more than two months of protests, which he said were not driven by outsiders but by Hong Kong people speaking out about their future.

On Wednesday in Hong Kong, three protest leaders surrendered to police and called for an end to the increasingly violent demonstrations. Students are still occupying two sites after clashes with police earlier this week as they tried to surround city government headquarters.

Russel described that flare-up as "alarming" and called for all sides to lower tensions.

The protesters are demanding China's government scrap its requirement that candidates in the 2017 election be approved by a panel chosen by Beijing.

Russel said China had not literally violated its commitment to allow "universal suffrage" by deciding to limit the pool of candidates, but it had fallen short of the aspirations of people in Hong Kong. A freer choice would enhance the legitimacy of the chief executive, he said.