When Canada’s Prime Minister Justin Trudeau told a group of executives that President Donald Trump wasn’t kidding about annexing Canada, he offered one reason: critical minerals.

Canada is rich in nearly three dozen critical minerals essential to modern technology and produces more than 60 minerals and metals including nickel, potash, aluminum and uranium.

The deposits are strewn across the country, which has a land mass about as big as all of Europe and second only to Russia. Ontario, Canada’s most populous province, is rich in nickel, chromite and copper. Quebec has lithium, rare earth metals and graphite. British Columbia has copper, molybdenum and niobium. The prairie provinces — Saskatchewan and Manitoba — have ultra high-grade uranium and potash. Much of this material ends up in the US, which was the biggest buyer of Canada’s critical minerals in 2023.

Since his election in November, Trump repeatedly has said Canada could avoid tariffs by becoming the 51st state. His move to lower his initial tariffs threats on raw materials in January — calling for 10% on imports instead of 25%, like most other Canadian goods — was a nod to the country’s reliance on its northern neighbor’s resources.

About a quarter of US uranium needs are fulfilled by gigantic mines in Saskatchewan, owned by companies like Cameco. More than 80% of US potash comes from Canada, including from Nutrien. And about 70% of US aluminum is supplied by plants in Quebec and British Columbia.

The US also relies on Canada for its military needs. Nickel from northern Ontario is shipped to the US for weapons manufacturing, along with zinc and germanium from Teck Resources Ltd.’s smelter in British Columbia.

Canada has long championed itself as the world’s hub for mineral explorers and developers. It’s home to nearly half of all publicly traded mining companies, along with schools, trade programs and professional associations dedicated to geological studies, mechanical engineering and mine construction.

But despite Canada’s mineral abundance, resource extraction is slowed by lengthy permitting times and countless regulatory hurdles. It can take five to 25 years to develop a mine in the country. And a lack of infrastructure in remote yet resource-rich regions means some deposits could take decades to develop.

Canada’s Ring of Fire — a vast, mineral-rich region in northern Ontario replete with nickel, copper and chromite — was discovered decades ago but has no clear timeline for development.

The sluggish pace has drawn criticism from business leaders and mining executives, who say Canada’s approach has slowed efforts to build a North American supply chain of the materials needed for electric vehicles, wind turbines, solar panels and military weaponry.

Meanwhile, China maintains a tight grip on key metals around the world, with ownership of major mines in Africa, Asia and South America. It also controls the bulk of global smelting and refining capacity, meaning that even Canadian metals producers will typically sell their material into China for processing.