The US Fish and Wildlife Service and the National Oceanic and Atmospheric Administration said the definition of "harm" in the Endangered Species Act should exclude "actions that impair the habitat of protected species."

Environmental groups said the rule change would allow timber, oil and mining activity, as well as other activities by individuals and the government, to destroy the habitats of endangered animals.

"For 50 years, the ESA has saved numerous species -- including iconic American species like bald eagles, gray wolves, Florida manatees, and humpback whales -- from extinction," environmental law organization Earthjustice said.

"One key to this success has been its definition of harm, which recognizes the common-sense concept that destroying a forest, beach, river, or wetland that a species relies on for survival constitutes harm to that species," it said, adding that the group was prepared to challenge the proposal in court.

"There's just no way to protect animals and plants from extinction without protecting the places they live, yet the Trump administration is opening the flood gates to immeasurable habitat destruction," said Noah Greenwald, codirector of endangered species at the Center for Biological Diversity.

"Without a prohibition on habitat destruction, spotted owls, sea turtles, salmon and so many more imperiled animals won't stand a chance," said Greenwald. "Trump is trying to drive a knife through the heart of the Endangered Species Act."

The proposal will now be open to public comment for 30 days.

Since its 1973 enactment, the Endangered Species Act has been credited with saving iconic species such as the gray wolf, bald eagle and grizzly bear from extinction.

President Donald Trump ran on a platform that promised to roll back environmental regulations that crimp economic development.

In February, Interior Secretary Doug Burgum issued a call for proposals to unleash US energy, potentially opening up fragile landscapes from the Arctic to the Grand Canyon and even national monuments for exploitation.

Days later, Trump said his administration aimed to cut about 65 percent of staff at the Environmental Protection Agency.