Emmanuel Macron said for the first time on Monday the opening ceremony of the Paris Olympics could be moved from the River Seine to the national stadium, in the event of a security threat.

Instead of teams sailing down the Seine on barges, the ceremony could be “limited to the Trocadero” building across the river from the Eiffel Tower or “even moved to the Stade de France”, the French President said.

The Paris organisers have devised a ceremony unprecedented in Olympic history, breaking from the tradition of the Games opening in the main stadium.

But with war raging in Ukraine and Gaza, the event on July 26 leaves teams potentially vulnerable to attack. French authorities have, for example, mentioned the possibility of an attack by drone.

So far, organisers have denied it could be moved to a different venue, if authorities believed there was a possibility of it being targeted.

“This opening ceremony... is a world first. We can do it and we are going to do it,” Mr Macron said in an interview with broadcasters BFMTV and RMC.

But, he added, “there are Plan Bs and Plan Cs”, including moving it to the Stade de France to the north of Paris, the main venue for the Olympics where the rugby sevens and athletics will be held.

“We will analyse this in real time,” Mr Macron added.

Any such relocation would be a huge undertaking and would deprive the Paris Olympics of their defining image.

More than 300,000 spectators are expected to attend the ceremony, with a further 200,000 watching from buildings along the Seine.

So far, all countries have said they plan to take part in the river parade, including the most risk-averse such as the United States and Israel.

Mr Macron also said he would do “everything possible” to have an Olympic truce during the Games – an historic tradition that ensures peace reigns for the duration of the event.

“We want to work towards an Olympic truce and I think it is an occasion for me to engage with a lot of our partners,” he said.

Mr Macron said he had a target of France finishing in the top five in the medals table for the Olympics and among the top eight nations for the Paralympics, which begin on August 28.