BILLINGS, Mont. (AP) — A federal judge in Montana has given the Trump administration until late 2019 to analyze reduced mining in the nation's most productive coal fields as a way to fight climate change.

The Tuesday order from U.S. District Judge Brian Morris in Great Falls applies to the Powder River Basin of Montana and Wyoming. The region supplies about 40 percent of the nation's coal, much of it from massive strip mines on public lands.

Morris turned down a request from environmentalists to halt new coal leasing until the review is completed. Lease sales already had slowed considerably over the past decade as demand for coal has declined.

Government officials had argued unsuccessfully that climate change could be addressed at individual mines rather than across the region.