Chinese President Xi Jinping has said there’s no reason to change Hong Kong’s “one country, two systems” formula of governance.

He made the comments on a rare visit to the global financial hub after swearing in the city’s new leader, John Lee, on Friday.

Britain returned Hong Kong to Chinese rule on July 1, 1997, with Beijing promising wide-ranging autonomy, unfettered individual rights and judicial independence at least until 2047.

China’s critics accuse authorities of trampling on those freedoms, unavailable on the authoritarian mainland, with a sweeping national security law imposed by Beijing on the city in 2020 after mass pro-democracy protests the year before.

British Prime Minister Boris Johnson and U.S. Secretary of State Antony Blinken said on Thursday that China had failed to meet its handover commitments.

China and Hong Kong reject the accusations, saying the law “restored order from chaos” so that the city could prosper.

Xi said the “one country, two systems” formula was successful under China’s “comprehensive jurisdiction.”

“For this kind of good system, there is no reason at all to change it. It must be maintained over the long term,” Xi said.

The Chinese President says Hong Kong’s development cannot be delayed again, and any interference must be eliminated.