U.S. officials have again been faulted by a federal judge for failing to adequately consider the potential climate change effects of expanding a massive coal mine in the sagebrush-covered hills of southeastern Montana.

U.S. Magistrate Judge Timothy Cavan recommended in a Monday ruling that the Interior Department be given 240 days to re-analyze the expansion.

But Cavan said mining shouldn't be stopped in the interim, frustrating environmentalists who have campaigned for years to curtail coal production from the huge strip mines in the Powder River Basin of Wyoming and Montana.

A final decision is up to U.S. District Judge Susan Watters.

If she adopts Cavan's recommendation, it would mark a setback to the Interior Department's attempts to downplay the climate change impacts of burning fossil fuels extracted from public lands.

In the Montana case, government officials asserted that burning the coal would have little effect on global emissions. That claim was first made by Interior officials under President Barack Obama and has been carried forward under President Donald Trump.

Cloud Peak Energy's Spring Creek Mine near Decker is the largest coal mine in Montana and the tenth largest in the U.S. based on 2017 production volumes, according to the Energy Information Administration.

The public land in dispute was leased by the Wyoming-based company in 2007. It's located in a sparsely populated area dominated by ranching and mining.