The US Department of the Interior announced a new rule on Friday that limits future oil and gas activities in Alaska’s National Petroleum Reserve, which spans 23 million acres. The rule amends existing federal regulations that the Bureau of Land Management uses to protect the reserve from environmental harm and gives the bureau more authority to cut back on oil and gas exploitation.

The bureau will issue no new oil and gas leases on 10.6 million acres of the reserves. For existing leases on 13.6 million acres, the bureau will assess new oil and gas projects more critically before approving them. For example, the agency will delay or deny new projects if necessary to prevent “significantly adverse effects” on the reserve’s environment.

Public commenters to the proposed rule—of which there were many—asked the agency to exempt existing leases from the changes. But it responded as follows:

[W]hile the terms of an existing lease and approved development project or permit would not be affected by the rule, a valid lease does not entitle the leaseholder the unfettered right to drill wherever it chooses…nor does it give the leaseholder the right to produce all economically recoverable oil and gas on the lease. Future development of an existing lease is, by its terms, subject to additional terms and conditions.

US Secretary of the Interior Deb Haaland commented, “[T]hese decisions will help biological, cultural, historic and subsistence resources, safeguarding the way of life for the Indigenous people who have called this special place home since time immemorial.” Environmental groups also welcomed the rule. Jeremy Lieb of Earthjustice “applaud[s] this move and call[s] for even bolder action to keep the fossil fuel industry out of the Arctic, for the sake of the climate and future generations.”

But the rule also drew heavy criticism. US Senator Dan Sullivan (R-AK) noted that the US would become more dependent on foreign sources of oil and gas, such as Iran, China and Russia. US Representative Sattler Peltola (D-AK) also disagreed with the ban on new leases in the 10.6 million acres. She said:

Closing off [that area] is a huge step back for Alaska, failing to strike a balance between the need for gap oil and natural gas and legitimate environmental concerns, and steamrolling the voices of many Alaska Natives in the decision-making process….Alaska has a wealth of natural resources that can be responsibly developed to help boost domestic manufacturing and innovation—in the end, it should be up to Alaskans to decide what they want developed in their regions.

The new rule moves in the opposite direction of developments from last year, when US President Joe Biden approved an $8 billion oil development. The move drew criticism from environmental groups.