"94% of municipalities are at risk of flooding, landslides, coastal erosion," Fabrizio Curcio told La Stampa newspaper, adding that "all of Italy is at risk," Reuters reported.
Curcio spoke after a mudslide devastated the southern Italian holiday island of Ischia on Saturday, causing the deaths of at least seven people.
He said Ischia was at greater risk because many of its houses were built illegally, but stressed that other parts of Italy with fewer land planning violations were also vulnerable.