By KEVIN FREKINGWASHINGTON (AP) — Citing fears of a Donald Trump presidency, environmental groups are urging President Barack Obama to stay busy in his final weeks. He is listening. With his days in office numbered, Obama has pushed ahead with several executive actions aimed at protecting the nation's land, air and water, even as he acknowledges his successor may try to undo the work before the ink is dry. The president has been cheered on by environmental groups and advocates braced for a new uphill fight in the next administration, and criticized by those who say an outgoing president shouldn't use his final days to stop what they say is the responsible development of the country's natural resources. In the three weeks since Trump's election, the Obama administration has moved to block for several years new oil and gas drilling in the Arctic Ocean, canceled 25 oil and gas leases in western Colorado and halted new mining claims on 30,000 acres near Yellowstone National Park. In a bid to curb methane emissions, the administration finalized regulations clamping down on oil companies that burn off natural gas on public lands. Meanwhile, the Corps of Engineers has delayed a decision on an oil pipeline to cross under a reservoir in North Dakota, saying it wants more study and tribal input. The president also is considering designating more national monuments. In recent months, the administration has dispatched various high-ranking officials to California, Utah and Oregon specifically to gain public feedback. Obama notes that several of his administration's actions have long been in the works — subject to public comment and notice — and are not a reaction to Trump's victory. "These aren't things that we've been surprising people with. They're well-considered. They're the right thing to do. They're part of my task of finishing my work," the president said at a recent news conference.