Any activities in Hong Kong seen as threatening China’s sovereignty and stability would be “absolutely impermissible,” Chinese President Xi Jinping said in a speech marking 20 years since the city became a semi-autonomous Chinese region after its handover from the UK, Reuters reported.

He pledged Beijing’s support for the “one country, two systems” blueprint, under which Hong Kong controls many of its own affairs and retains civil liberties including free speech.

 At the same time, Xi Jinping said Hong Kong had to do more to shore up security and boost patriotic education.

"Any attempt to endanger China's sovereignty and security, challenge the power of the central government ... or use Hong Kong to carry out infiltration and sabotage activities against the mainland is an act that crosses the red line and is absolutely impermissible," Xi said.

He added that Hong Kong “cannot afford to be torn apart by reckless moves or internal rifts.” 

“Now that Hong Kong has returned to China, it is all the more important for us to firmly uphold China’s sovereignty, security and development interests,” he said.