The practices involve partial or total removal of external genitalia for cultural or other non-medical purposes and can result in infections, infertility and sometimes death, a U.N. release said Saturday.
"The practice persists because it is sustained by social perceptions, including that girls and their families will face shame, social exclusion and diminished marriage prospects if they forego cutting," the statement said. "These perceptions can, and must, change."
The U.N. points to progress in recent years as communities and families started taking action and demanding change. Success in some countries has been a result of culturally sensitive efforts in communities "encouraging change from within," the U.N. said.
In Senegal, the practice declined 65 percent after public declarations against it, the U.N. said.
The U.N. estimates 120 to 140 million women have been subject to this harmful and dangerous practice and 3 million girls continue to be at risk each year, its release said.