The $US 1bn line would be built through an isolated area with few roads and challenging terrain, crossing wide river flood plains which are often swamped in the summer, and skirting the perimeter of the Pacaya – Samiria National Reserve, where road construction is prohibited.

Technical studies are due to be completed this month and an environmental impact assessment is also expected to be approved in the coming weeks.

The project is expected to be tendered as a build-operate-maintain concession through Peru's private investment agency Proinversión, and companies from Canada, China, and Brazil have reportedly expressed an interest in bidding.