SIOUX FALLS, S.D. (AP) — A federal judge has asked attorneys when they'll be ready for trial in a gambling-related lawsuit filed by the Flandreau Santee Sioux Tribe against the state of South Dakota.

The lawsuit was filed more than three years ago. It alleges the state has unfairly prevented the tribe from adding slot machines at its Royal River Casino at Flandreau.

U.S. District Judge Lawrence Piersol tells both sides that he wants to schedule a trial date and needs to know when attorneys will be ready.

Federal law allows Indian tribes to conduct the same kind of gambling that is allowed elsewhere in the state after they negotiate a gaming compact with the state. Tribes in South Dakota began opening casinos after state voters in 1989 approved gambling in Deadwood.