The San Carlos Apache tribe and other Native Americans say the mine would destroy sacred land where they hold religious ceremonies. Elected officials in nearby Superior, Arizona, say the mine is crucial for the region's economy.

The House Natural Resources Committee late on Thursday folded the Save Oak Flat Act into the $3.5-trillion reconciliation spending measure. The full House could reverse the move and the legislation faces an uncertain fate in the US Senate,

If approved, the bill would reverse a 2014 decision by former President Barack Obama and Congress that set in motion a complex process to give Rio federally-owned Arizona land that contains more than 40 billion pounds of copper in exchange for acreage that Rio owns nearby.

Former President Donald Trump gave the land swap final approval before leaving office in January, but successor Joe Biden reversed that decision, leaving the project in limbo.

The final reconciliation budget is expected to include funding for solar, wind and other renewable energy projects that require immense volumes of copper. Electric vehicles use twice as much copper as those with internal combustion engines. The Resolution mine could fill about 25% of the demand for US copper.

Superior Mayor Mila Besich, a Democrat, said the project seems increasingly stuck in "bureaucratic purgatory".

"This move seems contradictory to what the Biden administration is trying to do to address climate change," said Besich. "I hope the full House does not allow that language to stay in the final bill."

Rio said it would continue consultation with local communities and tribes. Rio CEO Jakob Stausholm plans to visit Arizona later this year.

Representatives for the San Carlos Apache and BHP Group, which is a minority investor in the project, could not immediately be reached for comment.