President Donald Trump signed an executive order Wednesday ordering a review of the status of tens of thousands of acres of federally protected public lands — a controversial move likely to draw fire from environmental groups and others.

The president, joined at the Department of the Interior by Interior Secretary Ryan Zinke and Vice President Mike Pence, called out past "abuse" of the Antiquities Act, which gives the president unilateral authority to designate national monuments.

"The Antiquities Act does not give the federal government unlimited power to lock up millions of acres of land and water and it's time we ended this abusive practice," the president said.

The order focuses on the past 20 years of national monument designations outlined in the Antiquities Act and spanning more than 100,000 acres, administration officials said.

In the crosshairs: the controversial Bears Ears National Monument — which Trump said he's heard is "beautiful."

The Utah monument, which was designated by President Obama, includes 1.3 million acres of land and will be the central focus of the interim review due back to the president within 45 days, Interior Secretary Ryan Zinke told reporters in a briefing on Tuesday evening.

Republican critics of Bears Ears have called for the federal designation to be rescinded and for the land to be given back to the state.

Bears Ears derives its name from two rock cliffs that resemble ears on a bear's head. It holds sacred cultural value to Native American peoples and includes archaeological sites.

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The Colorado River winds around the northern reaches of the proposed Bear Ears National Monument, with Canyonlands National Park in the background, viewed from Dead Horse Point State Park near Moab, Utah on Nov. 12, 2016. Jim Lo Scalzo / EPA file

“In the case of significant public land use, we feel the public should be considered. That’s why the president is asking for a review,” Zinke said in a Tuesday evening briefing with reporters, repeatedly stressing the need for local communities and state officials to have a voice in the process. In the case of Bears Ears, he said that the federal government should coordinate with Utah officials and lawmakers.

In signing the order, Trump said he was directing Zinke "to end these abuses and return control to the people — the people of Utah, the people of all of the states, the people of the United States."

"Everyday we are going to continue pushing ahead with our reform agenda to put the American people back in charge of their government and their lives," he said.

The fear on the part of some environmentalists and Native American groups and administration critics regarding the review is that it could be a step toward rescinding or altering their designation as federally protected monuments, including possibly reducing the size of the protected lands, and that it could open up the territories to exploitation by the oil and gas industries.

Bears Ears "was the first opportunity that American citizens had for Native American tribes, not one tribe, but five with support from other federally recognized tribes, asking to preserve and protect this land," Shaun Chapoose, chairman of the Ute Indian Tribe Business Committee told the Salt Lake Tribune and other publications in a recent conference call. "This is troubling for all Americans. Once you destroy these types of resources, these habitats, these places that are untouched, you can never go back."

Environmental groups were similarly concerned.

“Leave it to Trump to take aim at an American tradition and principle that is beloved by bipartisan communities — public lands, waters and monuments," Greenpeace's U.S. senior climate and energy campaigner Diana Best said in a statement. "By potentially rolling back safeguards for lands and waters that are currently protected from destructive development for generations to come, Trump is carving up this beautiful country into as many corporate giveaways for the oil and gas industry as possible. People in this country who cannot afford the membership fee at Mar-a-Lago want safe water they can drink and public lands for their communities to enjoy."

Zinke affirmed Tuesday, as he did during his Senate confirmation hearings, his opposition to the sale or transfer of public lands to states or private groups, and he pushed back on arguments the review could set the stage for an assault by the oil and gas industries as a “false narrative.”

Blaming a “polarized” media for the claim, Zinke stressed "the core of this is to make sure public has a voice."

While the president has the ability to designate public lands as national monuments, it’s unclear whether the Antiquities Act allows for the White House to rescind or diminish the size of previously designated monuments.

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More likely, the administration could make the case for trimming the size of the national monuments — something Zinke alluded to during the briefing.

He highlighted a portion of the 1906 law that said the president should "designate the smallest area compatible with proper care and management of the objects to be protected."

That the average size of monuments designations has increased over the years "should be worthy of notice," Zinke pointed out.

Introducing the vice president Wednesday, he was clear about how he saw the executive order's function. "his executive order does not remove any monuments. And this executive order does not weaken any environmental protections on any public lands," he said.

In keeping with the administration’s interest in using executive orders to keep campaign promises as Trump nears his 100th day in office on Saturday, the Interior Secretary said the review is, “another example of the president doing exactly what he’s said in his campaign promises.”

Zinke estimated that about 30 monuments will be reviewed.