China has strongly opposed and condemned a so-called joint statement issued by the UK and certain other countries commenting on the sentencing of anti-China figure Joshua Wong Chi-fung by the Hong Kong High Court, a spokesperson for the Chinese Embassy in the UK said on Friday.

The UK, together with the United States, Canada and Australia, issued the statement, making what China described as unwarranted comments on the case and interfering in Hong Kong affairs and China's internal affairs.

"China firmly opposes and strongly condemns such an act, and has made solemn representations to the UK side," the spokesperson said.

He further stressed that the facts of Joshua Wong’s crime of conspiracy to collude with a foreign country or external elements to endanger national security were clear and the evidence conclusive.

The judicial authorities of the Hong Kong Special Administrative Region (HKSAR) had handled the case and passed sentence in accordance with the law, which was "lawful, proper and beyond reproach."

"Hong Kong affairs are purely China's internal affairs. The rule of law in Hong Kong must not be undermined. No foreign country has the right to make irresponsible remarks on the matter," the spokesperson noted.

He added that the Chinese government remains unwavering in its determination to safeguard its national sovereignty, security and development interests and to implement One Country, Two Systems.

Any attempt to disrupt Hong Kong’s progress from stability to prosperity or to destabilise Hong Kong is doomed to fail, he said.

China urged the UK to stop shielding and glorifying criminals, and to stop interfering in Hong Kong affairs and China’s internal affairs under any pretext.