Argentina, Brazil, Chile and Peru have signed a cooperative pact on strategic minerals, seeking to coordinate the development, financing and international positioning of the region’s lithium, copper and rare-earth resources. The agreement builds on Argentina-Chile efforts under their revived 1997 Mining Integration and Complementation Treaty, which could support $20.7 billion in investment and add 540,000 tonnes to annual copper output. Brazil is pursuing regional supply-chain integration through a technical cooperation agreement with the Development Bank of Latin America and the Caribbean, while Peru’s mining associations have joined discussions on a common strategy. The initiative comes as the United States and European Union promote friend-shoring to reduce dependence on China’s dominant mineral-processing industry. The Lithium Triangle of Argentina, Bolivia and Chile contains more than 50% of the world’s known lithium reserves. Implementation could face obstacles including Argentina’s economic volatility, Brazil’s regulatory changes and mining protests in Peru. An earlier account identified an Aug. 28 joint declaration involving Bolivia rather than Brazil, creating a discrepancy in the reported composition of the agreement.