Cerro Colorado produced 71,700 tonnes of copper in 2019, or approximately 1.2% of Chile’s total.

“This measure is necessary to maintain a viable operation during the years that remain … which will be marked by high uncertainty and financial volatility,” the company said in a statement.

BHP said the new plan would mean a gradual reduction in staff that would begin this year and span the coming four months.

The company said it would nonetheless continue “looking for medium and long-term alternatives that would allow it to extend its mining operation beyond 2023.”

The mine, which operates in a water-parched region of northern Chile, is seeking to replace its use of groundwater with desalinated sea water from the nearby Pacific.

BHP also operates the sprawling Escondida copper mine in Chile, the world’s largest, as well as the nearby Spence copper mine.