US Secretary of State Marco Rubio on 3 June 2025 told American lawmakers that critical minerals have become a central pillar of US diplomacy, with embassies worldwide now actively working to secure supply chains and reduce dependence on China. Testifying before the House Appropriations Subcommittee on National Security, Department of State and Related Programs, Rubio said the Trump administration has elevated the issue to the forefront of its foreign policy agenda.

What Rubio told lawmakers

‘In every embassy around the world, critical minerals are a key component of our diplomacy,' Rubio said, framing the minerals race as the next frontier of US-China strategic competition beyond trade and technology.

The Secretary described critical minerals as essential to the future of advanced manufacturing, artificial intelligence, defence systems, semiconductors and clean energy technologies — sectors where Beijing currently dominates mining, refining and processing.

Building alternative supply chains

Rubio said Washington is working with partners across multiple regions to develop alternative supply chains. He pointed to recent diplomatic initiatives, including the Critical Minerals Ministerial, which he said drew ‘three dozen or more countries'.

Crucially, the US strategy extends beyond access to mineral deposits. ‘The ability to process those materials into a usable product' has become equally important, Rubio said, describing refining capacity outside China as a pillar of economic and national security planning.

The China challenge in developing markets

Rubio argued that many countries seeking infrastructure and industrial development have historically had few alternatives to Chinese-backed projects. ‘The only people showing up are Chinese companies,' he said, describing a recurring pattern across the developing world.

In response, the US is promoting American and allied alternatives across mining, processing, transportation and logistics infrastructure, often leveraging financing mechanisms and partnerships with like-minded nations to back strategic projects in mineral-rich regions.

Why hyper-concentration worries Washington

Rubio said supply-chain concerns now extend beyond minerals to other sectors where production has become heavily concentrated. ‘We simply have a hyper concentration' in certain industries, he warned, cautioning that single-supplier dependence creates compounding economic and strategic risks.

The urgency has grown as governments race to secure inputs for electric vehicles, battery manufacturing, renewable energy systems and emerging AI-linked technologies — all of which rely on a narrow basket of minerals where China controls the bulk of global processing.

What happens next

The State Department is expected to deepen bilateral and multilateral engagements on mineral security in the coming months, with diplomats tasked with mapping vulnerabilities and connecting partner governments to non-Chinese investment options. The success of that push will likely shape how quickly the US and its allies can blunt Beijing's leverage over the technologies of the next decade.