President Barack Obama has created two new US national monuments, bringing vast desert areas under federal protection.

Bears Ears and Gold Butte National Monuments protect over one million acres (0.4 million hectares) of sacred sites, spectacular scenery, and important natural and cultural resources in the desert landscapes of Utah and southern Nevada, the White House said Wednesday.

Obama, whose term in office ends January 20 when President-elect Donald Trump is inaugurated, has protected more than 550 million acres of public lands and waters, which the White House said was "more than any other president."

Gold Butte is fabled for its ancient rock art, sweeping vistas and twisted pastel-colored sandstone formations.

Environmentalists generally praise greater federal protection of land and water.

But many critics -- especially in Western areas where the government owns much of the land -- tend to see such moves as grabbing land in a way that may not be fair to all.

And in the case of Bears Ears, it will mark the first time the federal government will co-manage a national monument with Native American tribes.

The Hopi, Navajo, Uintah and Ouray Ute, Ute Mountain Ute and Pueblo of Zuni will together have responsibility for protecting an area that contains remnants of ancestral Pueblo sites dating back more than 3,500 years.

"We have always looked to Bear's Ears as a place of refuge, as a place where we can gather herbs and medicinal plants, and a place of prayer and sacredness," Russell Begaye, president of the Navajo Nation, told reporters.

"These places -- the rocks, the wind, the land -- they are living, breathing things that deserve timely and lasting protection."