OKLAHOMA CITY (AP) — The Cherokee Nation has appealed a tribal court decision that voided a constitutional amendment denying citizenship to non-Native American descendants of tribal members' former black slaves.

The tribe announced Tuesday that it would ask the Cherokee Nation Supreme Court to consider a Jan. 14 tribal district court ruling which nullified the 2007 voter-approved amendment requiring tribal citizens to have a Native American ancestor listed on the Dawes Roll.

The district court found the amendment violated an 1866 treaty between the tribe and the federal government that granted citizenship to the freedmen and their descendants.

Tribal Attorney General Diane Hammons says Cherokee citizens have the ultimate authority to define tribal citizenship.

Attorney Ralph Keen, who represents the freedmen's descendants, says he's confident the high court will uphold the district court decision.