President Xi has pledged Beijing's firm support for Hong Kong's policein punishing what he calls "violent criminals."
Speaking on the sidelines of a summit in Brazil on Thursday, he said the continuous violent activities seriously challenge China's "One country, Two systems".
Although he didn't specify how the central government would impose its will, Xi noted that Beijing is more than determined to oppose any external force interfering in Hong Kong's affairs.
He then reiterated that "stopping the violence and restoring order is Hong Kong's most urgent task" at the moment.
While he was delivering his remarks, pro-democracy protests in Hong Kong continued Thursday for a fourth consecutive weekday.
Almost 60 people were injured on Wednesday night including a 70-year-old man who eventually died after being hit in the head with a brick.
Riot police fired teargas and student protesters barricaded themselves inside universities, which will be closed until Sunday due to the turmoil.
"I am a student, I am a university student. I haven't expected I would get involved in such dangerous atmosphere. Because I want to protect my home. This is Hong Kong, this is our only place to live.''
The clashes have become so intense that international students including South Koreans are leaving the city, as several universities cancelled classes for the rest of the semester.
Meanwhile, Korea's foreign ministry readjusted the travel alert for Hong Kong from level one 'Blue' to level two 'Yellow' as of Friday, warning travelers to reconsider visiting the country, rather than just paying extra attention to their personal safety.
The ministry said it will keep a close eye on Hong Kong's security situation and decide whether to readjust the alerts.
KIM Bo-kyoung, Arirang News.