China said on Thursday it supports improving the system and mechanism related to the constitution and basic law of Hong Kong and Macau, in comments likely to stir concern that it could take measures to tighten its grip on Hong Kong.
The former European colonies returned to Chinese rule in the late 1990s under a system aimed at preserving their economic systems and ensuring their autonomy, known as "one country, two systems".
But in Hong Kong in particular, the political system has been thrown into question by student-led pro-democracy protests that went on for months last year and have shown signs of building up again in recent weeks.
"We will push for the long-term stability of one country, two systems ... and continue to support the improvement of implementing the systems and mechanisms of the constitution and basic law," Wang Yang, the ruling Communist Party's fourth-ranked leader and head of the Chinese People's Political Consultative Conference, said in a speech.
He did not elaborate. Hong Kong's "basic law" is its mini constitution.
Wang's remarks came at the opening of a session of the government advisory body that meets in parallel with parliament, which starts its annual session on Friday and will lay out policy targets and initiatives for the year.
Britain returned Hong Kong to China in 1997. The former Portuguese colony of Macau returned two years later.
The high degree of autonomy promised to Hong Kong for 50 years under the "one country, two systems" arrangement has helped it thrive as a financial centre, while Macau is a major gambling centre.
But many people in Hong Kong fear that Beijing is whittling away at its freedoms, worries that fuelled the sometimes violent protests last year. The protests have ebbed since January because of the novel coronavirus outbreak.