The Biden administration announced a proposal Wednesday to strengthen the Endangered Species Act, including repealing Trump-era rules that loosened protections for vulnerable species.

The US Fish and Wildlife Service, along with National Oceanic and Atmospheric Administration's National Maritime Fisheries Service, has proposed clarifying the standards for how the agencies list and reclassify species to ensure that the economic impact of doing so will not be a factor in their process. The Fish and Wildlife Service has also proposed reinstating a "base level of protection" or a "safety net" for all threatened species -- which was removed by the Trump administration -- though the agency will keep the option of providing additional species-specific rules.

"The Endangered Species Act is the nation's foremost conservation law that prevents the extinction of species and supports their recovery," Fish and Wildlife Service Director Martha Williams said in a statement. "These proposed revisions reaffirm our commitment to conserving America's wildlife and ensuring the Endangered Species Act works for both species and people."

In 2019, the Trump administration curbed environmental regulations, including how the Fish and Wildlife Service and NOAA consider whether species qualify for protections and which habitats deserve special protections. CNN previously reported that the changes had the potential to significantly lengthen how long it takes for a species to become protected, which could further endanger them. The Trump administration, however, argued that the changes allowed for the focus to be on the "rarest species."

The Biden administration in June 2021 announced plans to revise the Trump-era regulations, which had faced legal challenge from a coalition of environmental groups.

Republicans have long criticized the Endangered Species Act and opposed strengthening protections for vulnerable habitats and species, arguing that it impacts drilling, logging and mining, and has hampered economic growth in those industries.

Last month, the Senate passed two resolutions to undo Biden administration changes to two Trump administration wildlife rules: one governing what a habitat definition is, and one on reclassifying a wildlife species.

But environmental groups, including law group Earthjustice, cheered the latest move.

"These are promising steps toward restoring the purpose and power of the Endangered Species Act, and getting these protections back is why we challenged the harmful Trump rules for the past four years," said Earthjustice attorney Kristen Boyles in a statement. "By mending the rules interpreting the ESA, the Biden administration can significantly help us address the worsening biodiversity crisis and celebrate the 50th anniversary of the Act."

The Endangered Species Act was passed by Congress in 1973, and among the animals that it has protected from extinction are the bald eagle, American alligator, grizzly bear, American peregrine falcon, southern sea otter, humpback whale, green sea turtle, gray wolf, Florida manatee and California condor.