US president Joe Biden will create a national monument covering nearly one million acres (400,000 hectares) of federal land next to the Grand Canyon National Park, all within the state of Arizona, blocking any future uranium mining.

The change in the area’s status comes after a 20-year mining ban was established encompassing virtually the same boundaries by the Obama administration in 2012.

The new monument’s protected standing will have no impact on existing mining operations or claims within its limits.

But the move drew criticism from the uranium industry and some politicians, who say the US needs domestic uranium resources to reduce its reliance on imports.