Macron scales Notre-Dame's rooftop

In the hours after the blaze, Macron promised a distraught French nation that the cathedral, which dates back to the 12th century, would be rebuilt and later said it would be reopened in some form to worshippers by 2024.

More than 700 days after workers scrambled to shore-up Notre-Dame's flying buttresses, stabilize the bell towers and install hundreds of movement sensors, the effort to make the site secure ahead of restoration is almost complete.

From the rooftop, now largely covered by a complex scaffolding structure, work platforms and in places a tarpaulin "umbrella," Macron peered down into the cathedral's damaged transept and thanked workers on the site.

"We're all impressed with what we see, with the work that has been achieved in two years," Macron told a group of workers with the Paris skyline behind him. "Bravo and thank you."

General Jean-Louis Georgelin, the former army chief of staff named by Macron to head the renovation said the works were reaching a critical juncture.

Restoration work would begin before the end of 2021, he said.