Authorities implemented widespread road closures and security measures in Wan Chai North in the early hours of Wednesday in anticipation of a visit to Hong Kong by President Xi Jinping to mark the 25th anniversary of the handover.

There has been no official word on whether Xi will come to the territory in person to oversee the swearing-in of the next administration, but the police said on Tuesday that in the event that he does come, they will offer him personal protection and escort his motorcade.

The police said people and vehicles heading to the area around the Hong Kong Convention and Exhibition Centre – where the ceremonies are to be held – will be subject to security checks.

Core security zones will also be set up wherever Xi goes and footbridges and flyovers will be closed temporarily as his motorcade passes by.

The MTR Corporation said Exhibition Centre Station will be closed from the early hours of Thursday and won't reopen until 2pm on July 1.

Assistant police commissioner Lui Kam-ho said the force will adjust its security plan accordingly if the state leader doesn't visit Hong Kong in the end.

"We are maintaining close contact with our counterparts to see if there are any updates. If there are any latest changes in our president's visit programme, we will correspondingly adjust our security measures and deployment to minimise the inconvenience caused to members of the public," he told a press conference.

A no-fly zone will be set up over Victoria Harbour and some other areas, while the flying of drones will be banned across the whole of Hong Kong.

Lui said in coming to this decision the police had taken into account a number of factors, including practice on the mainland and overseas, drone attacks abroad, and their own intelligence.

"We need to keep the activities or itineraries of our president confidential. In order to balance the rights of people to use drones and our responsibility to ensure the personal safety of our president during his stay in Hong Kong, we considered the decision is a well balance of the two needs," he said.

The police said they hadn't received any applications for public assemblies on July 1.

The League of Social Democrats (LSD) said it had decided not to stage a protest that day after its volunteers and activists were asked to attend a meeting with national security police.

Lui sidestepped questions as to whether the force has discouraged the LSD or other groups from organising any protests.

"We fully respect the rights of people, the freedom of expression, staging protest, public meetings, etc. We have taken reasonable measures to ensure these rights are protected," he said, adding that there will be a public activity area outside the main security zone.