The closure marks the latest blow for Freeport, the world`s largest publicly traded copper producer, after Peru`s government shuttered its mines last month because of the coronavirus outbreak, which has claimed more than 110 000 lives across the globe and infected nearly two-million.

The Chino mine, in New Mexico`s southwest corner, produced 175-million pounds of copper last year, making it the company`s third-largest North American mine by production.

Three of the mine`s employees tested positive for the virus earlier this month. Freeport said on Sunday that more employees have now tested positive, adding the contagion is not "widespread," without providing specific numbers.

New Mexico state officials were first alerted to the additional cases on Saturday.

"We have asked that Chino mines employees not report to work until further notice after learning about additional employees testing positive for Covid-19," Freeport spokeswoman Linda Hayes said in a statement to Reuters.

The Phoenix, Arizona-based company plans to work with local and state officials to determine when to reopen the mine. Employees will receive paid leave for any missed scheduled shifts while Freeport reviews Chino operations, Hayes said.