GRAND CANYON VILLAGE - US President Joe Biden will curb land development on a stretch of nearly one-million acres (405 000 ha) near Arizona's iconic Grand Canyon, a move intended to cement his environmental credentials in the electoral battleground state.

Biden, who arrived in Arizona aboard Air Force One on Monday evening, will create the Baaj Nwaavjo I'tah Kukveni - Ancestral Footprints of the Grand Canyon National Monument, a designation disparaged by some officials and mining interests but long sought by tribes that trace their origin to the lands.

The new area, whose name is drawn from the languages of the nearby Havasupai and Hopi tribes, straddles the existing Grand Canyon National Park, where the US government forcibly removed Native Americans a century ago. It boasts bison, bald eagles and sites held as sacred by several tribes.

It is also home to about 1% of the country's known uranium reserves, according to a Biden administration official, who said existing rights to mine, hunt, fish and graze will be respected. The land is currently covered by a two-decade mining moratorium.

Biden, a Democrat seeking re-election in 2024 who has been endorsed by groups including the Sierra Club, has nonetheless angered some environmental groups with moves like the approval of ConocoPhillips' $7-billion oil and gas drilling project Willow in Alaska.

"From day one, I have taken action on the most ambitious climate and conservation agenda in our country's history," Biden said in a statement, saying his decision "honors our solemn promise to Tribal Nations to respect sovereignty" and "preserves America's iconic landscapes for future generations."

While US national parks can be created only by an act of Congress, national monuments can be designated unilaterally by presidents and a century-old federal law meant to protect sacred sites, artifacts and historical objects.

Arizona has emerged as a key battleground state that the Biden campaign plans to target with money and personnel. Biden won the state by less than 1 percentage point in 2020, four years after former President Donald Trump took the state by 3.5 percentage points.

Biden's Western swing marks a stark contrast to the controversy swirling around Trump, his top Republican rival, who was indicted last week for the third time in four months, this time for wide-ranging attempts to overturn the 2020 election.

Biden has declined to comment on his opponent's legal troubles.