A coalition of 17 states, the District of Columbia and New York City sued the Trump administration on Wednesday to block its recent rollback of the Endangered Species Act.

The legal effort, led by the attorneys general of California, Massachusetts and Maryland, aims to safeguard one of America’s most important laws for protecting imperiled plants and animals.

“Now is the time to strengthen our planet’s biodiversity, not to destroy it,” California Attorney General Xavier Becerra said at a press conference Wednesday. “But instead of choosing to protect these species, the Trump administration has decided to backslide.”

Finalized last month, the Trump administration’s industry-friendly new rules weaken the popular and successful 1973 law by making it easier for federal agencies to remove species from the protected list. They also allow for economic impacts to be considered when making decisions about granting species protection, limit agencies’ ability to account for the impacts of future climate change and diminish protections for future threatened species.

Notably, the sweeping changes came on the heels of a United Nations report that found humans have driven up to 1 million species around the globe toward extinction.

“As we face a climate emergency and global extinction crisis threatening more than a million species, the Trump Administration is gutting Endangered Species Act protections to pave the way for oil and gas developments,” Massachusetts Attorney General Maura Healey said in a statement. “We are suing to defend federal law and protect our imperiled wildlife and environment.”

The Trump administration has said the overhaul will “modernize” and “improve” the law, and that recovering populations of imperiled species is the ultimate goal. But several high-ranking officials in the Interior Department detest the law, claiming it is “a sword to tear down the American economy” and voicing support for repealing the act entirely.

“These are long overdue and necessary regulatory changes that will recover more imperiled species facing extinction than previously accomplished over the span of this law,” Interior spokesman Nick Goodwin said in a statement responding to the lawsuit. “We will see them in court, and we will be steadfast in our implementation of this important act to improve conservation efforts across the country.”

Among other things, the lawsuit argues that the Trump administration’s revisions unlawfully limit when species can receive protections under the law and insert economics into the decision-making process. Without action, it’s possible that future generations will only be able to see species like the southern sea otter or the desert tortoise in a museum, Becerra said.

“We filed because we have a strong case,” Becerra said. “We filed because we intend to win.”

The states’ lawsuit comes one month after eight environmental groups filed their own lawsuit, arguing that the changes violate the purpose of the ESA and that the administration failed to analyze the impact of its revisions.

The ESA was passed with strong bipartisan support in 1973 and has succeeded in preventing 99% of listed species from going extinct, including the Yellowstone grizzly bear, bald eagle and black-footed ferret. Today, it protects more than 1,600 plants and animals, as well as the habitats critical to their survival.

This story has been updated.