A bald eagle takes flight at the Museum of the Shenandaoh Valley in Winchester, Va. While once-endangered bald eagles are booming again in the Chesapeake Bay, the overall trajectory of endangered species and the federal act that protects them isn't so clearcut. (Scott Mason/The Winchester Star via AP, File)

WASHINGTON — The Trump administration moved on Monday to weaken how it applies the 45-year-old Endangered Species Act, ordering changes that critics said will speed the loss of animals and plants at a time of record global extinctions .

The action, which expands the administration’s rewrite of U.S. environmental laws, is the latest that targets protections, including for water, air and public lands. Two states — California and Massachusetts, frequent foes of President Donald Trump’s environmental rollbacks — promised lawsuits to try to block the changes in the law. So did some conservation groups.

Pushing back against the criticism, Interior Secretary David Bernhardt and other administration officials contend the changes improve efficiency of oversight while continuing to protect rare species.

“The best way to uphold the Endangered Species Act is to do everything we can to ensure it remains effective in achieving its ultimate goal — recovery of our rarest species,” he said in a statement. “An effectively administered Act ensures more resources can go where they will do the most good: on-the-ground conservation.”

Under the enforcement changes, officials for the first time will be able to publicly attach a cost to saving an animal or plant. Blanket protections for creatures newly listed as threatened will be removed. Among several other changes, the action could allow the government to disregard the possible impact of climate change, which conservation groups call a major and growing threat to wildlife.

Commerce Secretary Wilbur Ross said the revisions “fit squarely within the president’s mandate of easing the regulatory burden on the American public, without sacrificing our species’ protection and recovery goals.”

The Endangered Species Act is credited with helping save the bald eagle, California condor and scores of other animals and plants.