China imposed export restrictions on certain rare earth elements on Friday as part of its response to President Donald Trump's tariff measures. The move could disrupt U.S. access to critical minerals essential for technologies ranging from smartphones to electric vehicle batteries.

What To Know: China restricted exports of seven rare earth elements to all countries, including the U.S. The newly restricted rare earths are: samarium, gadolinium, terbium, dysprosium, lutetium, scandium and yttrium.

According to the U.S. Geological Survey, China produces about 90% of the world's refined rare earths. Approximately three-quarters of the rare earths imported into the U.S. come from China. The export restrictions are not a full-blown ban but rather allow China to restrict access through the issuance or denial of export permits.

If China restricts access to rare earth elements, the U.S. could face shortages in key industries, including national defense, clean energy, EVs and electronics.

Mark A. Smith, CEO of the rare earth mining company NioCorp Developments Ltd. (NB  0.00%), called the export restrictions a "precision strike by China against Pentagon supply chains" and warned that "these aren't just metals - they're bottleneck elements."

"This is not a mere supply chain hiccup, it's a geopolitical earthquake in slow motion ... And with Russia and China tightening coordination, this may mark the start of a material cold war fought not with tanks, but with export licenses and embargoes," Smith added.

Stocks To Watch: Shares of USA Rare Earth, Inc. (USAR  0.00%) are soaring Friday as investors speculate that China's latest restrictions could accelerate subsidies for domestic mining. USA Rare Earth describes itself as establishing domestic rare earth and critical minerals supply, extraction and processing capabilities in the U.S.

MP Materials Corp. (MP  0.00%) ,which owns and operates the only rare earth mining and processing site of scale in North America, should also be monitored.

Investors can also monitor the rare earth elements industry through the VanEck Rare Earth and Strategic Metals ETF (REMX  0.00%), which focuses on global firms from China, the U.S. and Australia.