The police chief spoke ahead of a potentially large pro-democracy demonstration on Sunday and following nearly six months of sometimes violent protests in Hong Kong, sparked by a now-withdrawn bill allowing extradition to Mainland China.

Tang said the police will take a "humanistic" approach to minor incidents but warned of resolute measures against more violent actions, and added that he hopes the march will be peaceful.

Hong Kong, a major financial hub, had enjoyed relative calm for the past few weeks since local elections late last month delivered an overwhelming victory to pro-democracy candidates.

Tang was appointed to his position in November. He was in Beijing for a "courtesy visit" to meet mainland officials, the Hong Kong police said in a short statement on Thursday.

He said he met with Zhang Xiaoming, the head of the Hong Kong and Macau Affairs Office, and Zhao Kezhi, China's minister of public security.

The protesters are angry at what they see as Chinese meddling in the freedoms promised to the former British colony when it returned to Chinese rule in 1997.

China denies interfering, says it is committed to the "one country, two systems" formula put in place at that time and has blamed foreign forces for fomenting unrest.

Earlier on Saturday Tang observed a flag-raising ceremony in Tiananmen Square, according to video footage carried by Hong Kong broadcaster Cable TV.

"I am very excited to see the country's flag fly and to feel the country's greatness," he told reporters. "I would like to thank... President Xi Jinping (for his) unwavering support of the Hong Kong police strictly enforcing the law."

REUTERS