The US administration announced Monday a 20-year ban on new mining projects around the Grand Canyon, in a move aimed at protecting the prized tourist area from the impact of uranium extraction.

Interior Secretary Ken Salazar said the move would "protect the iconic Grand Canyon and its vital watershed from the potential adverse effects of additional uranium and other hard rock mining on over one million acres," or 400,000 hectares.

The move "is the right approach for this priceless American landscape," Salazar said.

"People from all over the country and around the world come to visit the Grand Canyon. Numerous American Indian tribes regard this magnificent icon as a sacred place and millions of people in the Colorado River Basin depend on the river for drinking water, irrigation, industrial and environmental use.

"We have been entrusted to care for and protect our precious environmental and cultural resources, and we have chosen a responsible path that makes sense for this and future generations."

Jane Danowitz of the Pew Environmental Group said the announcement means "Americans can celebrate today that the Grand Canyon is protected for future generations to enjoy."

She also called for reform of "the nation's antiquated mining law," which she said gives the industry "unfettered access to the majority of public lands in the west."

Salazar imposed a two-year moratorium on new mining around the Grand Canyon in 2009, to give his department time to study a long-term ban. In June, he extended the moratorium for an additional six months.

The ban does not prohibit previously approved uranium mining, and new projects that could be approved on claims and sites with valid existing rights, the agency said.

Other types of mineral extraction and geothermal energy could be done in the area, the agency said.

A number of Republican lawmakers from the region have opposed the ban.

Senator John McCain said in a statement the move "is a devastating blow to job creation in northern Arizona."

McCain, who has argued that the ban would undermine a compromise on wilderness protection hammered out in the 1980s, said the decision "is fueled by an emotional public relations campaign pitting the public's love for the Grand Canyon against a modern form of low-impact mining that occurs many miles from the Canyon walls and in no way impacts the quality of drinking water from the Colorado River."

McCain and other lawmakers from Arizona and Utah sent a letter last year to Salazar claiming any new ban would create a "de facto wilderness" zone in a region that "conservationists previously agreed would remain accessible to the mining industry."

McCain's group has introduced a bill to enshrine what he called a "historic agreement" in 1984 "that designated parts of the Arizona Strip as wilderness and restored other lands to reasonable and safe uranium mining uses."