China is facing mounting criticism over a planned security law for Hong Kong which would make it a crime to undermine Beijing's authority in the territory.
The UK and US said at a private session of the UN Security Council that the law would curtail the city's freedoms.
China, which blocked a formal meeting, warned them to "stop interfering".
Hong Kong's autonomy is guaranteed by the 1997 agreement under which it was returned to China from the UK.
It enjoys some freedoms - of the press and association - unseen in mainland China.
But there are fears the proposed law - which has sparked a wave of anti-mainland protests - could end Hong Kong's unique status.
This week, Britain said that if China went forward with the law, it could offer British National (Overseas) passport holders a path to UK citizenship.
There are 350,000 BNO passport holders in Hong Kong who currently have the right to visit the UK for up to six months without a visa.
On Friday, the UK Home Office confirmed the new rights could be given to up to three million people with BNO status - as long as they applied for and were granted a passport.
China says all BNO passport holders are Chinese nationals, and if the UK changes this practice, it would violate international law.
https://www.bbc.co.uk/news/world-asi...eporting-story