Inaction by Congress and the Trump administration is threatening a fund that supports coal miners suffering from black lung disease.

The Associated Press has learned that lawmakers let an automatic tax rate cut on coal take effect in January.

Federal budget officials say that has cut the flow of money so sharply into the fund that it might not have enough to cover the cost of doctors visits and medicines for about 25,000 retired coal miners starting next year.

The cuts to the fund could save coal operators hundreds of millions of dollars a year.

President Donald Trump vowed to save the coal industry during the 2016 campaign and has repeatedly praised miners.

The shrinking of the fund comes amid a surge in black lung disease among Appalachian coal miners.