OKLAHOMA CITY (AP) — Oklahoma City officials agreed Tuesday to accept an agreement with the state of Oklahoma to complete and operate the unfinished American Indian Cultural Center and Museum.

But officials cautioned that completion of the 173,000-square-foot structure is still at least four years away. Construction is set to resume in June and the structure is not scheduled to be fully operational until 2020, said Blake Wade, executive director of the Native American Cultural and Educational Authority.

City council members voted 7-0 to accept the terms of legislation signed into law by Gov. Mary Fallin last year to complete and open the center, which is located on the banks of the Oklahoma River in downtown Oklahoma City.

Construction began in 2006 but has been dormant since 2012 when the project ran out of money and the Republican-controlled Legislature refused to allocate new funds. The state has already spent about $90 million on the project and, although incomplete, was paying about $7 million a year to maintain the property and make payments on earlier construction bonds.

Wade said completing the structure will cost another $80 million, a sum that will be shared by the state, the city, private donors and the Chickasaw Nation, which offered in December to partner with the city to help complete the stalled museum. The Oklahoma-based tribe operates the 109-acre Chickasaw Cultural Center in Sulphur.

"I’m extremely delighted that Oklahoma City, the state of Oklahoma and the Chickasaw Nation all came together to make this a reality," Wade said.

The agreement calls for the state to provide an additional $25 million in bonds for completion of the museum and transfer responsibility for its operation and maintenance to the city. The city will provide $9 million toward the structure’s completion.

Wade said another $31 million will be provided by private donors and that the Chickasaw Nation will provide the balance, about $15 million.

Bill Lance, secretary of Commerce for the Chickasaw Nation, said in a statement that the tribe has long supported the project and the agreement "is a significant step forward." Wade said he hopes all of Oklahoma’s 39 federally recognized tribes will play a role in completion and operation of the structure.

In its agreement with the city, the tribe has offered to provide up to $14 million over seven years for operation of the museum and will develop 143 acres of commercial property surrounding the center, Wade said. The tribe owns the WinStar World Casino and Resort in southern Oklahoma and has broad tourism and hospitality industry expertise, officials said.

"We’re certainly looking at all kinds of suggestions," Wade said. But casino activity is prohibited by the legislation adopted last year as well as the deed in which the city originally conveyed the property to the state in 2006.

Supporters have said the museum will be a world-class, Smithsonian-quality facility that will house collections from Oklahoma-based American Indian tribes, the National Museum of the American Indian in Washington and other tribal museums, and attract tourists from around the nation and the world.