Colombia currently only requires environmental permissions for projects in the exploitation and production phases.

The Portfolio consists of 22 royalties on the production of minerals from mines in North America, South America, Australia and Africa.

Rio’s copper leaching technology venture, Nuton, snapped up most of the McEwen Copper shares in the final tranche of a private placement.

Copper demand will increase by more than 50% between now and 2040, according to BloombergNEF.

The world's largest copper producer expects its output of the red metal to fall further next year amid project delays.

"We wouldn't have enough for it to be only public. It requires a lot of investment," Lopez Obrador said at a news conference.

The newly approved plan will cost the company $52 million in investments and measures taken to address six environmental infractions detected by Chile's regulator.