Tens of thousands of caribou cross these lands each year in the Arctic National Wildlife Refuge.
CNN  — 

Fifteen states are suing the Bureau of Land Management, its parent agency the Interior Department and Interior Secretary David Bernhardt for opening Alaska’s Coastal Plain up to oil and gas leasing in 2017 in what they say is a violation of environmental laws.

“Defendants’ insufficient environmental review and Record of Decision that opens the entire Coastal Plain to oil and gas leasing and development are unlawful,” the states’ attorneys general wrote in a filing Wednesday.

The move comes after Bernhardt announced plans last month for an oil and gas leasing program in the Arctic National Wildlife Refuge, clearing the way for drilling in the remote Alaskan area, a long controversial issue. Bernhardt said future leases of the federally owned land will make the entire 1.5 million acre Coastal Plain area available.

Interior Department spokesman Conner Swanson told CNN in a statement Wednesday that “this is a congressionally mandated energy development program that leaves ninety-two percent of the refuge completely off-limits to development,” adding: “The lawsuit is politically motivated and meritless, and we will see them in court.”

The 19 million-acre Arctic National Wildlife Refuge had been closed to oil exploration since 1980 due to concerns about the effect it would have on the region’s caribou, polar bears and other animals. But the Trump administration’s 2017 law required the department to hold two lease sales in the refuge by 2024.

The states of Washington, Massachusetts, California, Connecticut, Delaware, Illinois, Maine, Maryland, Michigan, Minnesota, New Jersey, New York, Oregon, Rhode Island and Vermont brought the lawsuit against the bureau on Wednesday.

“Defendants’ actions severely underestimate the avoidable and irreparable damage to vital habitat and pristine waters, imperil wildlife already struggling to thrive in a rapidly changing ecosystem, and increase greenhouse gas emissions at a time when our nation and the world drastically need to reduce emissions to mitigate the most extreme harms of climate change,” they wrote.

Environmental issues were at the forefront of President Donald Trump’s agenda this week. He emphasized his environmental accomplishments during an appearance in the battleground state of Florida on Tuesday, even as his administration has worked extensively to dismantle key environmental protections. Trump also signed a moratorium on Tuesday extending an offshore drilling ban for Florida’s Gulf Coast, and extended the ban to Florida’s Atlantic Coast as well as the coasts of Georgia and South Carolina.

Over the past three and a half years, the administration has pulled out of the landmark Paris climate accords, rolled back regulations on carbon emission standards for coal-fired power plants, made the largest reduction in the boundaries of protected land in US history and changed Clean Water Act and Endangered Species Act protections.

CNN’s Betsy Klein, Gregory Wallace and Chandelis Duster contributed to this report.