Legislating on national security in the Hong Kong Special Administrative Region is undoubtedly within the remit of the central authorities, Hong Kong Chief Executive Carrie Lam Cheng Yuet-ngor said on Tuesday.

The Hong Kong leader pledged full support and cooperation from the SAR as the central government carries forward national security legislation in the city.

Speaking to reporters before the weekly Executive Council meeting, Lam dismissed speculation that the draft decision of the National People’s Congress on national security legislation in Hong Kong would “"erode"" the “"one country, two systems"" principle and the SAR’s high degree of autonomy.

On the contrary, the move is to ensure the successful implementation of the principle of “"one country, two systems"", by improving the related legal system and enforcement mechanisms in strict accordance with the national Constitution and the Basic Law, Lam said.

National security is a matter within the remit of the central authorities, she stressed. It is only legitimate for the NPC, as the highest organ of State power, to legislate on national security in the Hong Kong SAR, Lam said.

The SAR leader noted that the central government is unswerving and determined in carrying forward the legislation, and pledged that her administration will extend full support and cooperation, regardless of any possible difficulties.

Albert Chen Hung-yee, a law professor at the University of Hong Kong and a member of the Hong Kong SAR Basic Law Committee under the NPC Standing Committee, stressed that even though Article 23 of the Basic Law stipulates that the SAR should legislate on its own on safeguarding national security, it does not mean such legislative power is exclusive, or that the central government has given up or transferred such power.

The SAR failed to legislate after almost 23 years since its return to China, Chen noted. It is legitimate for the central government to exercise its power to legislate in order to deal with situations where national security has been seriously damaged in the SAR, Chen said.

The legal veteran hoped the new legislation would demonstrate the spirit of the “"one country, two systems"" principle, and respect the differences in legal systems between the mainland and the Hong Kong SAR.

In a statement issued late on Monday night, the Liaison Office of the Central People’s Government in the Hong Kong SAR pointed out that the violent protests on Sunday again demonstrated the necessity and urgency for a national security law in Hong Kong.

On Sunday, a large group of rioters wreaked havoc in Hong Kong by destroying public and private property and attacking police officers and passersby with bricks, umbrellas and glass bottles.

Stating that the rioters have been advocating “"Hong Kong independence"", a spokesman for the office warned the rioters and the forces behind them not to underestimate the central government’s determination to carry forward the national security legislation.

The central government is unswerving in safeguarding national sovereignty, security and development, and maintaining the prosperity and stability of the Hong Kong SAR, the spokesman said.

The central government is prepared to deal with any complicated situations, the spokesman said.

Major General Chen Daoxiang, commander of the People’s Liberation Army Hong Kong Garrison, said on Tuesday that his troops will resolutely carry out the central government’s policies and decisions, while upholding “"one country, two systems"" principle.