The bells of Notre Dame in Paris rang out together on Friday for the first time since a 2019 fire that devastated the historic cathedral, AFP reporters said.

The sound of the eight bells in Notre Dame's northern belfry came a month before the cathedral is to reopen following five years of painstaking restoration work in the wake of the blaze.

"This is a beautiful, important and symbolic step," said Philippe Jost, who runs the public body tasked with restoring the cathedral under challenging circumstances.

On the evening of April 19, 2019 Parisians and the world watched in horror as flames ravaged the world heritage landmark and then toppled its spire.

President Emmanuel Macron quickly set the ambitious goal to rebuild Notre Dame within five years and make it "even more beautiful" than before.

Some 250 companies and hundreds of experts were mobilised for a restoration costing hundreds of millions of euros.

Friday shortly before 10:30 am, the bells sounded one by one until all eight chimed in harmony.

"It's not perfect yet, but we will make it perfect," said Alexandre Gougeon who is in charge of the re-installation of the bells. "This first test was a success."

The 2019 fire destroyed part of the northern belfry, requiring it to be restored and the bells to be removed, cleaned of dust and lead, and then returned to their space.

The heaviest bell, called "Gabriel", weighs over four tonnes, and the lightest, "Jean-Marie", 800 kilogrammes.

A weekend of ceremonies is to mark Notre Dame's reopening on December 7 and 8.