The US Department of Defense has finalized a ban on the acquisition of tantalum metals and alloys from North Korea, China, Russia, and Iran.

The US Department of Defense, which had imposed a provisional ban since October 2020, has adopted the rule as final, noting that “with some exceptions” new rules “prohibit the purchase of any regulated materials smelted or produced in any of the regulated countries (North Korea, China, Russia and Iran), or any end products manufactured in any of the regulated countries”. After a two-year period during which the department received proposals and comments on the new rules from interested parties, the department approved the final text of the amendments on Thursday.

The corresponding notice was placed in the US Federal Register and the rules came into force as of August 25. 

The Pentagon said that reducing US dependence on tantalum from these four countries is a matter of national security because the rare element is an important part of the supply chain in the production of military and non-military systems used by the Defense Department.

Tantalum is a rare and hard metal that is often used to coat jet engines and other equipment exposed to extreme heat. Its heat-resistant and corrosion-resistant alloys are used in equipment for the chemical industry and heat exchangers for nuclear power systems as well as cryotrons -- a switch that operates using superconductivity and is installed in computer systems.