The US Commerce Department has launched an investigation into whether or not imports of titanium sponge are a risk to security.
Titanium sponge is a porous form of titanium that is created during the first stage of the production process. It is a key component in military aircraft, space vehicles, missiles and munitions.
However, a petition from US manufacturer Titanium Metals Corp claims imports are harming the industry at home because only one facility currently has the capacity to process ore into the spongy material, plus it cannot be stored because it degrades.
Imports currently account for more than 60 per cent of US titanium sponge consumption, much of which come from Japan.
The Trump administration has agreed to investigate the possible security risks of such imports under Section 232 of the Trade Expansion Act of 1962, a law dating back to the Cold War era.
Apparently, the Commerce Department hopes to block rises in imports and the case could end in tariffs or other trade barriers.
This may generate friction between the US and Japan as both nations prepare to begin a new round of negotiations on a possible trade deal.