The Trump administration on Friday finalized a rule rescinding a regulatory definition of "harm" under the Endangered Species Act that had included habitat modification that actually kills or injures protected wildlife.

Interior Secretary Doug Burgum and Commerce Secretary Howard Lutnick cast the rescission as a return to statutory text; environmental groups called it an invitation to development that will imperil at-risk species and said they would sue.

The U.S. Fish and Wildlife Service and NOAA Fisheries, the fisheries office of the National Oceanic and Atmospheric Administration, jointly rescinded the 1981 definition without replacing it. As a result, "harm" under Section 9 of the Endangered Species Act will be interpreted under the law's prohibition on directly injuring or killing protected wildlife.

The prior definition captured habitat modification or degradation that actually kills or injures wildlife by impairing breeding, feeding, or sheltering.

Federal officials said the definition had been used to obstruct energy production, logging, mining, and private land use, generating permitting costs that the administration said were untethered from the law Congress passed.

Burgum said in a statement that federal agencies had "abused the ESA to obstruct lawful land use and burden American families and businesses," adding that the change "restores common sense, respects private property, provides much-needed certainty for landowners and follows the statute Congress actually passed."

Lutnick in a statement framed the action as removing "overly broad and burdensome regulations that have restrained our fishermen for too long."

The Interior Department said existing permits and incidental take statements remain valid and that directly injuring or killing listed wildlife remains prohibited.

The agencies said the repeal followed the Supreme Court's 2024 decision in Loper Bright v. Raimondo, which ended the long-standing practice of courts deferring to federal agencies' interpretations of ambiguous laws.

The Interior Department said the earlier definition of "harm" amounted to an unlawful regulatory intrusion that interfered with private property rights.

The repeal is expected to face a legal challenge. In 1995, the Supreme Court upheld the habitat-based definition of "harm" in Babbitt v. Sweet Home, a precedent E&E News reported is expected to play a central role in litigation over the rule.

Earthjustice said it would sue. Attorney Kristen Boyles said in a statement that "truly harmful projects that will imperil species" risked "slipping through the cracks" and "being allowed to go forward."

The Center for Biological Diversity has also signaled it will challenge the rescission, which environmental groups say cannot survive Sweet Home.

As of Friday, the final rule had been announced by the Interior and Commerce departments but had not yet been published in the Federal Register.