BEIJING, May 22 (Xinhua) -- A draft decision on establishing and improving the legal system and enforcement mechanisms for the Hong Kong Special Administrative Region (HKSAR) to safeguard national security was submitted to China's national legislature for deliberation on Friday.

Wang Chen, vice chairman of the Standing Committee of the National People's Congress (NPC), explained the draft decision to the third session of the 13th NPC, which runs from May 22 to 28.

Since the return of Hong Kong to the motherland, China has been firmly implementing the principles of "one country, two systems," "the people of Hong Kong governing Hong Kong," and a high degree of autonomy, according to the explanatory document delivered by Wang.

The practice of "one country, two systems" has achieved unprecedented success in Hong Kong, says the document.

But the increasingly notable national security risks in the HKSAR have become a prominent problem, the document says, citing activities that have seriously challenged the bottom line of the "one country, two systems" principle, harmed the rule of law, and threatened national sovereignty, security and development interests.

Law-based and forceful measures must be taken to prevent, stop and punish such activities, according to the document.