Japan plans to test rare-earth mining at a depth of 6 km underwater, according to reports.
Japanese officials are preparing a full-scale extraction test, following the discovery of high-value rare earths in a deep-sea mining project.
An analysis of mud from off Minamitorishima island, Japan found medium and heavy rare earth elements accounted for about 54% of the total rare earth content.
The discovery supports efforts to reduce reliance on Chinese supplies, according to statements.