Washington, April 25 — Senior Democratic lawmakers in the United States have raised urgent national security alarms over the transfer of federally owned land in Arizona to a foreign-controlled mining company, warning that the deal hands control of one of America's largest untapped copper deposits to an entity with deep financial ties to China. The lawmakers have formally demanded an immediate review by the Committee on Foreign Investment in the United States (CFIUS), citing both strategic mineral risks and proximity to critical US military infrastructure.

Lawmakers Demand CFIUS Review of Resolution Copper Deal

In a formal letter addressed to Treasury Secretary Scott Bessent, Congresswoman Maxine Waters and three other senior ranking members called for an emergency review of the transfer of thousands of acres of US Forest Service land to Resolution Copper Mining, LLC. The site in question, known as Oak Flat, sits in Arizona and holds one of the nation's most significant undeveloped reserves of copper and other critical minerals.

The lawmakers argued that the land transfer effectively places a strategically vital resource under the operational influence of companies with substantial commercial exposure to Beijing. Their letter stated that the statutory language authorizing the transfer "explicitly failed to acknowledge" the true ownership structure behind Resolution Copper.

BHP and Rio Tinto's Deep China Connections Under Scrutiny

Resolution Copper Mining, LLC is jointly owned by global mining behemoths BHP and Rio Tinto — two of the world's largest foreign mining corporations. The lawmakers pointed out that both BHP and Rio Tinto generate more than half of their revenue from exporting minerals to the People's Republic of China (PRC), creating a structural dependency on Chinese markets.

More critically, the letter highlighted that Rio Tinto's largest single shareholder is a Chinese state-owned enterprise, raising concerns that Beijing could exert indirect influence over decisions affecting the Oak Flat mining project. This detail, lawmakers argued, transforms what appears to be a routine land transfer into a potential foreign influence operation over American critical mineral infrastructure.

This development comes amid a broader pattern of congressional scrutiny over Chinese investment in US resource sectors. Notably, similar concerns were raised in 2023 over Chinese-linked entities acquiring land near military bases in states including North Dakota and Texas, prompting bipartisan legislative pushback.

Military Proximity and Emerging Weapons Infrastructure Raise Stakes

The Oak Flat site is located within 100 miles of Luke Air Force Base, one of the US military's premier fighter pilot training facilities. Federal regulations governing foreign investment explicitly flag proximity to sensitive defence installations as a key risk factor in CFIUS evaluations.

The lawmakers further warned that planned mining operations at the site would require extensive underground infrastructure — including tunnels, transport corridors, and electrical grid systems — that could introduce exploitable vulnerabilities in a region of growing strategic importance.

Adding another layer of concern, the letter noted that a hypersonic missile manufacturing and testing facility may be developed in the vicinity of Oak Flat, dramatically elevating the national security calculus around foreign-linked industrial activity in the area. The convergence of critical mineral extraction, military training operations, and next-generation weapons development in the same geographic zone is what the lawmakers describe as a "potential major national security concern."

Copper's Critical Mineral Status and the Domestic Processing Gap

Copper has been formally designated a critical mineral by the US Geological Survey, underscoring its indispensable role in defence manufacturing, electric vehicles, power grid infrastructure, and advanced electronics. The metal is foundational to the US military's modernization agenda and the broader green energy transition.

However, the lawmakers flagged a significant legal loophole: current US law does not require copper extracted from the Oak Flat site to be processed or sold within the United States. This means that even as American land and resources are used for mining, the resulting output could legally be exported — potentially to China itself — without any domestic economic or security benefit.

This gap in the law mirrors a wider vulnerability that analysts have long flagged in US critical mineral policy, where extraction rights do not automatically guarantee domestic supply chain security. Critics argue this structural flaw undermines the very rationale for designating minerals as "critical" in the first place.

Parallel Alarm Over US-China Science and Technology Agreements

In a separate but related development, Republican lawmakers sent a letter to the State Department raising concerns about oversight gaps in US-China Science and Technology Agreements (STAs). They warned that there is currently "no centralized system in the US government which tracks these sub-agreements," leaving American research and intellectual property exposed.

The Republican letter stated that China has "historically weaponized science and technology cooperation to steal Intellectual Property (IP) and trade secrets" from partner nations, and that existing STA frameworks provide insufficient safeguards against such exploitation.

Taken together, the dual congressional warnings — one from Democrats on mining, one from Republicans on science — reflect a rare moment of bipartisan convergence on the threat posed by Chinese access to American strategic assets, whether physical or intellectual.

As CFIUS comes under renewed pressure from both sides of the aisle, analysts expect the Biden-era land transfer authorization to face intensified legal and legislative scrutiny in the coming weeks. The outcome of any CFIUS review could set a landmark precedent for how the US government evaluates foreign-linked access to critical mineral deposits on federal land going forward.