More than 1,000 rounds of tear gas were fired and many demonstrators were arrested during the latest round of protests that have paralysed the island city for six months.
Speaking at an global conference, he said, "We will continue to firmly support the chief executive in leading the Hong Kong Special Administrative Region government to govern in accordance with the law, firmly support the Hong Kong police in strictly enforcing the law, and firmly support the Hong Kong judicial bodies in severely punishing the violent criminals in accordance with the law".
Hong Kong has entered its first recession for a decade after months of anti-China protests and violent clashes.
Earlier on Saturday morning a group of around 500 people, mostly middle-aged and senior citizens, rallied outside the Hong Kong government's headquarters to show support for the police, who have been heavily criticised over their handling of the crisis. Student activists have barricaded themselves into university campuses and shut down major roads, but today an eerie calm descended.
Service remained partially suspended on at least three of Hong Kong's 12 rail lines because of damage to stations and other facilities, and numerous city's buses were not running.
Several universities have announced there would be no classes on campuses for the rest of the year.
On the same day, police shot a protester in the abdomen.
"Our campus has been occupied by masked protesters, including those from outside".
Protesters build a wall to block a road at The Hong Kong Polytechnic University, in Hong Kong on November 14, 2019.
The mainland Chinese students arriving from Hong Kong huddled with their suitcases, waiting for a bus to take them to temporary accommodation in this city across the border from the protest-wracked territory.
A statement by the Hong Kong government said Cheng suffered "serious bodily harm" but gave no details.
"However, any demand that universities can simply fix the problem is disconnected from reality: these complicated and challenging situations ... are reflections of Hong Kong-wide disagreement, and the government must take the lead with swift and concrete action".
As a rolling strike cripples the transport system of the famously frenetic city and fuels already intense clashes with police, hardcore protesters have bolstered their arsenal of Molotovs and bricks with an unlikely array of weapons.
Standing beside a black flag with the slogan "Liberate Hong Kong, Revolution of our Times", James Wong, 23, was among a handful of protesters still manning a bridge at Baptist University.
"I have had students cry talking about what is happening. But the PLA should not leave their base because this is Hong Kong territory".
Hong Kong is a city divided and reactions to the movement from inside the PLA garrison reflected that schism. "We don't touch them (the PLA barracks) we don't know what kind of weapons they have and their mindset is also different from Hong Kong police" said a 24-year-old student protesters who identified himself by the surname Leung. On Monday, police blamed a "rioter" for dousing a man in petrol and setting him on fire.
He remains in a critical condition.