Critical Metals Corp. agreed to buy a controlling interest in the Tanbreez rare earth deposit in Greenland as it strives to serve a US-aligned supply chain for strategic metals.

The US-listed company is acquiring up to 92.5 per cent of the equity in Tanbreez in a deal valued at US$211 million,, according to a statement Monday. Tanbreez is one of the world’s largest known rare earth assets and the project has a license to from Greenland’s government to mine the deposit, the statement said.

Shares of Critical Metals rose as much as 10 per cent to US$11.31 in New York before paring gains.

The US and allies have raised concerns over China’s dominance for producing and refining rare earth elements, key materials used in aerospace and defence applications. China processes nearly 90 per cent of the world’s rare earths and no other nation has the technological capacity to refine these metals at the moment. China moved in December to ban export of a range of rare earth technologies, making it difficult for others to build processing capacity.

“The US and Nato really want a supply chain of rare earths that comes outside China and has nothing to do with China,” Critical Metals Chief Executive Officer Tony Sage said in an interview, adding that the plan for Tanbreez is to produce for western nations. He said the firm also plans to build a processing facility in Greenland or the US in the coming years.

The cost to build Tanbreez is about US$500 million with an additional US$150 million needed to start mining, according to a person familiar with the matter.

The acquisition is expected to be structured as a two-stage issuance of Critical Metals common shares, as well as an initial US$5 million purchase of shares from Tanbreez’s primary owner, Gregory Barnes. Critical Metals’ largest shareholder, European Lithium Ltd., will retain a 7.5 per cent ownership in Tanbreez.