Xi was visiting the city ahead of the 25th anniversary of the handover of Hong Kong from the UK to China, on 1 July.

The territory has seen huge changes since the last time Xi made a similar trip, in 2017. The city was gripped by mass protests, sometimes violent, starting in summer 2019.

The next year Beijing imposed a sweeping national security law on Hong Kong, which the British government described as "grave and deeply disturbing".

Scores of pro-democracy advocates and politicians have been arrested under the law.

Xi arrived in the city on a high speed train and was greeted by supporters waving Chinese and Hong Kong flags.

"I'm very happy to be in Hong Kong," Xi said on arrival.

"It's been five years since I last visited, and in the past five years I've been paying attention to and thinking about Hong Kong."

Later, the Chinese president said that Hong Kong had been "reborn from the ashes" with "vigorous vitality".

"As long as we stick to the 'one country, two systems' framework, Hong Kong will certainly have a brighter future and will make new and bigger contributions to the great rejuvenation of the Chinese people," he said.

'One country, two systems' is the framework in which Hong Kong was returned to China 25 years ago, with the territory promised that its way of life would remain unchanged for 50 years.

On Friday, Mr Xi will swear in the global financial hub's new leader, John Lee, who takes over from Carrie Lam.

The Foreign, Commonwealth and Development Office hasn't commented about the anniversary of the handover so far but has regularly expressed concern about developments in Hong Kong.

In early May, the UK joined the G7 for a collective statement expressing "grave concern over the selection process for the Chief Executive... as part of a continued assault on political pluralism and fundamental freedoms".

In March, the government backed British judges who resigned from serving in Hong Kong's top courts due to an erosion of democracy and liberty caused by the new security law.

The same month, the British ambassador to the UN, Simon Manley, accused the Chinese government of continuing to "systematically... undermine rights and freedoms, in clear breach of the Sino-British Joint Declaration", adding: The UK remains committed to holding China to its international commitments."

The joint declaration was a treaty between the UK and China signed in 1984 which set the conditions in which Hong Kong was transferred to Chinese control and how the territory would be governed after 1 July 1997.

Hong Kong island had been a British colony since 1842 after it was ceded to the UK following the First Opium War. A 99-year lease for a part called the New Territories was subsequently granted in 1898, allowing British-controlled territory to be expanded.

The declaration set out how, after the handover, a special administrative region would be established that would be self-governing with a high degree of autonomy, except in foreign affairs and defence - hence "one country, two systems".

That was supposed to be incorporated into Hong Kong Basic Law, a constitution that set out how the territory would be governed, and that would remain unchanged until 2047.

In the wake of the introduction of Hong Kong's new security law, the UK government changed its rules on allowing overseas British Nationals in the territory to come to live in the UK, for what it said were the "UK's historic and moral commitment to those people of Hong Kong who chose to retain their ties to the UK".

As of the end of March, there had been 123,400 applications from British Nationals Overseas in Hong Kong to take up the opportunity for them and their family members to live, work and study in the UK.

Beijing and the Hong Kong government reject accusations that they have breached the earlier agreements, saying they
have "restored order from chaos" so that the city can prosper.