The U.S. Department of Justice’s Energy and Natural Resources Division filed a statement of interest on Thursday supporting the construction of a primary aluminum smelter in Inola, Oklahoma.

The filing came in response to a lawsuit brought by Oklahoma Attorney General Gentner Drummond against Century Aluminum Company and Aluminum Oklahoma. Drummond’s suit alleges environmental violations under state nuisance laws tied to the project.

ENRD argued that the concerns raised fall under the federal Clean Air Act and Clean Water Act, which require environmental permits for the smelter’s construction and operation. The division described the lawsuit as premature and said it threatens materials critical to national defense.

“This project advances national and economic security by reducing the country’s reliance on foreign sources of materials critical to the national defense,” said Principal Deputy Assistant Attorney General Adam Gustafson of ENRD.

The Inola facility would mark the first new primary aluminum smelter built in the United States in over 40 years. It is projected to become the largest such plant in the country and more than double domestic output. The Department of Energy awarded the project $500 million, citing its role in boosting production with an estimated 75 percent lower emissions than traditional smelters.

ENRD emphasized that a delay would increase U.S. dependence on foreign aluminum supplies and limit production of armor, aircraft, and munitions. The statement urged the U.S. District Court for the Northern District of Oklahoma to dismiss the case, noting that federal permitting processes provide the proper avenue for environmental review.

The project involves a joint venture at the Tulsa Port of Inola and has drawn attention for its potential economic impact and strategic importance to domestic manufacturing.