The Cherokee Nation in Oklahoma says it's filed a petition for a rehearing of the South Carolina Supreme Court's decision allowing the adoption of a girl of Cherokee heritage by a Charleston-area couple.
The Tahlequah-based tribe said Monday that the court's decision was "troubling."
Several American Indian groups are also preparing to sue over the decision.
The Native American Rights Fund, National Congress of American Indians and National Indian Child Welfare Association said Monday they want to try to protect the best interests of the now-3-year-old girl named Veronica.
The girl has been living in Oklahoma since 2011 when South Carolina justices said a federal law favored her being raised by her biological father, a member of the Cherokee Nation who has been pursuing custody of Veronica in Oklahoma.