Chile and Argentina Revive Treaty for Multibillion-Dollar Copper Hub

Argentina and Chile approved operating protocols to integrate three mega-mining projects across the Andes Mountains, advancing a legal framework designed to unlock more than US$20.7 billion in copper investment.

Officials from both countries convened in Santiago on Thursday (August 27) under the Mining Integration and Complementation Treaty, an agreement signed in 1997, but rarely used until the administrations of Chilean President Jose Antonio Kast and Argentine President Javier Milei revived it this year, according to a Reuters report.

During the meeting, the administrative commission signed specific additional protocols establishing concrete rules to share infrastructure and resources for the Vicuña, NexoAndino and Filo Sur projects. The mineral deposits for all three developments straddle the border between Argentina’s San Juan province and Chile’s Atacama region.

“The development of bi-national projects … creates enormous opportunities for Chilean suppliers, for the use of Chilean infrastructure, for providing services to the Argentine industry and for developing partnerships,” Joaquin Villarino, head of Consejo Minero, Chile’s mining council, said.

Argentine projects located near the Andes can potentially access Chilean ports and tap into the world’s largest copper-producing supply chain. This access is expected to reduce costs and shortens transport routes to the Pacific Ocean, accelerating mine construction and export capacity.

The Vicuña project integrates the Josemaría deposit in Argentina, Tamberías in Chile and Filo del Sol, which straddles the border. The asset is controlled by a joint venture between Lundin Mining (TSX:LUN,OTCPL:LUNMF) and major mining company BHP (ASX:BHP,NYSE:BHP,LSE:BHP).

Meanwhile, the newly authorized NexoAndino protocol combines the Los Helados project in Chile and Lunahuasi in Argentina, while Filo Sur allows exploration teams to unify operations across the border.

Since taking office in March 2026, the Kast administration in Chile has received more than US$24.3 billion in mining projects for environmental review to support its reform.

Meanwhile, Argentina is experiencing its largest copper investment cycle in history.

Seven copper projects totaling US$22 billion have already secured approval under Milei’s Large Investment Incentive Regime, known as RIGI, which guarantees 30 years of tax and currency stability.

Argentina has not produced copper since the Alumbrera mine closed in 2018.

However, Morgan Stanley (NYSE:MS) recently identified eight major copper developments across the country that could absorb US$44 billion in capital. The bank forecasts that Argentine copper production could reach 1.2 million metric tons annually by 2035, generating roughly US$26 billion in export revenue.

Representatives from several cross-border projects, including McEwen Mining (TSX:MUX,NYSE:MUX) subsidiary McEwen Copper’s Los Azules and Glencore’s (LSE:GLEN,OTCPL:GLCNF) El Pachón, are scheduled to meet in Santiago on Friday (August 28) to further discuss integration opportunities.

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Securities Disclosure: I, Giann Liguid, hold no direct investment interest in any company mentioned in this article.