Extensive damage is reported on Mayotte's power grid, water supply, communication systems, and at the airport after the cyclone's passage, with winds exceeding 60 meters per second.
Hundreds of residents have been reported dead, but the death toll may rise to several thousand according to the authorities.
I've never seen anything like it. Almost all of the island's inhabitants are affected in some way, says Vice Mayor Dhinouraine M'Colo Mainty to French Franceinfo.
President Macron announced late on Monday, after a crisis meeting, that he will travel to the French island group in the coming days.
"I declare national mourning, this tragedy affects us all", Macron wrote on X.
"Chaotic situation"
Extensive French aid is reaching Mayotte despite the difficulties – and the distance, 700 miles, from the French mainland. Another French territory, Réunion, is serving as a logistics base for the rescue operation. According to Réunion's prefect Patrice Latron, Mayotte's inhabitants are facing "an extremely chaotic situation, enormous destruction".
France's Social and Health Minister Geneviève Darrieussecq said on French Télématin that the hospital is "extremely damaged" and healthcare facilities destroyed.
France's Interior Minister Bruno Retailleau visited the disaster areas on Monday and said that large areas were "totally destroyed".
All slums, all shantytowns, there's nothing left of them, he said.
French soldiers
About 1,600 French soldiers and firefighters have arrived to participate in the rescue efforts.
The USA announced that the country is ready to provide humanitarian aid if needed.
The President of the Comoros, Azali Assoumani, has declared a week of mourning as many of those living on Mayotte come from the neighboring islands.
Mayotte has been ruled by France since the mid-19th century and is the country's poorest region. At least a third of the territory's 320,000 inhabitants live in shantytowns.
