At more than 480,000 square feet, the building aims to be among the top five largest zero carbon industrial buildings in Ontario.

Poilievre said that a Conservative government would also commit $1 billion over three years to build a road network to link the mining sites to Ontario's highway network and First Nations communities in the area.

The Cromwell Area Sewer Separation and Flood Mitigation project aims to address the increased risk of basement flooding and sewer overflows.

Mayor Olivia Chow said the "landmark agreement" will help reduce barriers to build housing and help secure affordable homes "for generations to come."

The Ontario government says there are more than 26,000 mining claims for the Ring of Fire held by 15 companies and individuals.