The EPA said it would “revisit aspects” of a 2017 regulation that aims to reduce visibility-inhibiting air pollution in national parks and wilderness areas.

The Environmental Protection Agency announced its plans in three letters posted on its website. The letters, dated Jan. 17, were sent to Alaska and power industry groups that petitioned the EPA to reconsider aspects of the regulation.

The Obama administration issued the regulation updating its regional haze requirements on Jan. 10, 2017, a little more than a week before the inauguration of President Donald Trump. Critics of the Obama-era changes included EPA Administrator...