WASHINGTON >> The top U.S. and Chinese diplomats publicly aired differences Wednesday over the protests in Hong Kong, where students want democratic changes to the electoral system.

Secretary of State John Kerry met at the State Department with China’s Foreign Minister Wang Yi as the standoff between students and authorities intensified in the Chinese territory — the stiffest challenge yet to Beijing’s authority since China took control of the former British colony in 1997.

The protesters oppose Beijing’s decision in August that all candidates in an inaugural 2017 election for the territory’s top post must be approved by a committee of mostly pro-Beijing local elites. Tens of thousands of people have rallyed against that decision in Hong Kong’s streets since late last week.

“We believe in open society, with the highest possible degree of autonomy and governed by rule of law, is essential for Hong Kong’s stability and prosperity, and we have high hopes that the Hong Kong authorities will exercise restraint and respect for the right of the protesters to express their views peacefully,” Kerry said.

Wang pushed back. He said the protests are “China’s internal affairs” and called on other countries to respect its sovereignty.

“I believe for any country, for any society, no one will allow those illegal acts that violate public order. That’s the situation in the United States, and that’s the same situation in Hong Kong,” he said, adding that Hong Kong’s administration has the capability to handle the situation in accordance with law.

The protesters say China is reneging on a promise that Hong Kongers would be allowed to choose their own leader starting in 2017. Kerry reiterated U.S. support for so-called universal suffrage.

Protesters warned Wednesday they will step up their actions if the territory’s top official doesn’t resign by Thursday, possibly occupying several important government buildings.

Chinese state media indicated the government may be losing patience with the protesters. China’s main TV broadcaster CCTV said all Hong Kong residents should support authorities to “deploy police enforcement decisively” and “restore the social order in Hong Kong as soon as possible.”

Wang is visiting Washington to prepare for a planned visit by President Barack Obama to a summit of Asia-Pacific economies that China is hosting in November.

Richard Bush, a China expert at the Brookings Institution, a Washington think tank, said China will be annoyed by the U.S. publicly raising its concerns over Hong Kong but won’t want the upcoming summit to be overshadowed by a crackdown on protesters.