U.S. wildlife officials are extending the Engendered Species Act to include the white rhinoceros, whose dwindling wild populations in Africa are at the mercy of poachers.
The white rhino was the last species of rhinoceros not covered by the act.
Without genetic testing, traffickers were able to sell the horns of other rhino species covered by the act as white rhino horn when it was unprotected.
Fish and Wildlife Service chief Dan Ashe says the United States is a transit point and market for products made of illegal rhino horn, which is ground up and sold in medicines or made into drinking cups.
But experts say rhino horn is made from the same material as human fingernails and is worthless as a cure for disease.