President Joe Biden delivered remarks at the League of Conservation Voters annual Capital Dinner on Wednesday.
Watch Biden's remarks in the player above.
In March, the Biden administration came under fire from environmental groups for approving the huge Willow oil-drilling project on Alaska's petroleum-rich North Slope.
The move by Biden quickly drew condemnation from environmentalists who said it flies in the face of the Democratic president's pledges.
The announcement came a day after the administration, in a move in the other direction toward conservation, said it would bar or limit drilling in some other areas of Alaska and the Arctic Ocean.
The Willow approval by the Bureau of Land Management would allow three drill sites, which would include up to 199 total wells. Two other drill sites proposed for the project would be denied. Project developer ConocoPhillips has said it considers the three-site option workable, "the right decision for Alaska and our nation" in the words of company chairman and CEO Ryan Lance.
Climate activists were outraged that Biden greenlighted the project, which they say put his climate legacy at risk. Allowing the drilling plan to go forward also would break Biden's campaign promise to stop new oil drilling on public lands, they say.