GILLETTE, Wyo. (AP) — The head of the U.S. Environmental Protection Agency toured a Wyoming coal mine and said regulations like those seeking to reduce greenhouse-gas emissions from power plants are more punitive than helpful.

Scott Pruitt visited Arch Coal's Black Thunder Mine Thursday at the invitation of Republican U.S. Sens. Mike Enzi and John Barrasso of Wyoming.

Pruitt visited as President Donald Trump's administration looks to roll back climate regulations proposed under President Barack Obama.

Pruitt said after the tour the Obama regulations go too far and it's not the EPA's job to use regulations to penalize certain forms of energy to help others.

Black Thunder is the second most productive U.S. coal mine and is located in a region that supplies about 40 percent of the nation's coal.