WASHINGTON — President Trump said on Thursday that his administration was answering “a call to action” by rolling back regulations on environmental protections, health care, financial services and other industries as he made a push to showcase his accomplishments near the end of his first year in office.

The remarks highlighted an area where Mr. Trump has perhaps done more to change the policies of his predecessor than any other, with regulatory shifts that have affected wide sections of the economy.

“We are just getting started,” Mr. Trump said, speaking from the Roosevelt Room of the White House. He described progress so far as the “most far-reaching regulatory reform” in United States history, a claim he did not back up.

“We have decades of excess regulation to remove,” he added. “To help launch the next phase of growth, prosperity and freedom, I am challenging my cabinet to find and remove every single outdated, unlawful and excessive regulation currently on the books.”