U.S. President Joe Biden will prevent or limit oil drilling in 13 million acres of Alaska and the Arctic Ocean, the Associated Press reported on Sunday, citing an administration official.

The reported move comes as Biden’s administration earlier this week said that it has not yet made a final decision on whether to approve ConocoPhillips’ COP.N massive Willow oil project in northwest Alaska.

According to AP, the plan has two parts. To start with, Biden will bar drilling in nearly 3 million acres of the Arctic Ocean, closing off the rest of its federal waters from oil exploration.

Citing the administration official, the report added that the administration will then develop new rules for more than 13 million acres in the National Petroleum Reserve – Alaska. The area includes the Teshekpuk Lake, Utukok Uplands, Colville River, Kasegaluk Lagoon and Peard Bay Special Areas.

The White House did not immediately respond to Reuters request for comment.

ConocoPhillips’ Willow project has support from the oil and gas industry and state officials eager for jobs, but it is opposed by environmental groups who want to move rapidly away from fossil fuels to combat climate change.