The Federation of Copper Workers (FTC) said there had been "alarming" numbers of infections at several of the country's mines.

Government will collect samples from mine sites to prevent companies seeking to undervalue production to pay less tax.

Nearly 70% of foreign-owned mining companies operating in Mexico are based in Canada.

Trafigura estimates that the virus has reduced mine supply by 400,000 tonnes.

The economics were boosted by the addition of resources as well as an improved process flow sheet.

China's steel association has called for an increase in domestic iron ore production as well as greater investment in exploration overseas to ensure supplies.

The kingdom's unused mineral resources are valued at $1.3 trillion.