PARIS - Paris will face major disruption ahead of the Olympics opening ceremony along the Seine on July 26, as organisers ramp up security measures to safeguard the event, the city's police chief said on Thursday.

Organisers hope the opening ceremony, in which 160 boats carrying athletes from around the world will travel a 6 kilometre route along the Seine river towards the Eiffel tower, will deliver a jaw-dropping spectacle. Some 300,000 spectators will watch from the banks of the Seine as a global audience tunes in on TV.

But the ceremony is also a major security headache, taking place against a backdrop of wars in Ukraine and Gaza. French President Emmanuel Macron has already floated the possibility of scrapping the river ceremony and reverting to at least two back-up plans if the security risks become untenable.

Paris residents with a view of the Seine can invite friends to watch the opening of the 2024 Summer Games from their balconies, but should prepare for heavy traffic and limited movement, Paris police chief Laurent Nunez said at a press conference.

Adjacent metro stations, most river crossings and all water traffic will be halted in the week before the open-air ceremony, Nunez said, adding that some bridges will remain open "in order not to cut Paris in two halves."

Everyone who wants to access the immediate surroundings of the Seine in the week before the Games will need to sign up on an online platform, Nunez said. Local residents hoping to access their homes, which are among the most prestigious addresses in France, will need to do the same.

Paris mayor Anne Hidalgo, who also spoke at the event said the disruption would impact around 20,000 residents and business owners.

Asked about Macron's comments earlier this month, Nunez said his teams were still working on the 'Plan A' of the river ceremony.

"As of today, we have no reason to be worried," Nunez said. REUTERS