Workers prepare to remove a statue from the damaged Notre Dame cathedral, in Paris, Friday, April 19, 2019.
A large swath of the island in the Seine River where Notre Dame is located was officially closed Thursday by police, who cited "important risks" of collapse and falling objects.
The Paris prosecutors' office ruled out arson and possible terror-related motives - it is now being treated as an accident.
"The worst has been avoided, but the battle isn't fully won yet", Macron said.
Le Parisien newspaper has reported that investigators are looking at whether the fire could have been linked to a computer glitch, or related to the temporary elevators used in the renovation work, among other things.
French President Emmanuel Macron has pledged to rebuild Notre Dame within five years "even more attractive than before".
Two days earlier, Macron had vowed to rebuild the landmark and expressed his hope the task could be achieved within the next five years to coincide with the 2024 Summer Olympics. The area had been unofficially blocked off since the fire.More news: Chelsea striker Giroud: I have to meet Marina
More news: Ocasio-Cortez quits Facebook, calling social media a 'public health risk'
More news: Spal 2 - 1 Juventus - Match Report & Highlights
He said the monument is still being consolidated with wooden planks to support some fragile parts of the walls.
Bells rang around Wales as a show of solidarity and sorrow following the devastating fire at Notre Dame. As the fire raged on, a crowd gathered near the cathedral to sing "Ave Maria".
According to the BBC, these items included what is claimed to be the crown of thorns worn by Jesus before his crucifixion and also a tunic, which King Louis IX is said to have worn when he delivered the crown of thorns to Paris.
"During our history, we have built cities, ports, churches. It was spreading quickly".
"The country and the entire world were watching us and you were exemplary", Macron said in his speech at the ceremony.
Nicolas Vaux-Montagny and Angela Charlton in Paris contributed.