Japan took a bold step toward securing critical minerals on Monday as a government-backed deep-sea mining vessel set sail on a pioneering mission to extract rare earth–rich mud from the ocean floor near the remote Minamitori Island, highlighting Tokyo’s growing urgency to reduce its dependence on China.
The test drilling ship Chikyu departed from the port city of Shizuoka for a month-long expedition to waters surrounding the tiny coral atoll, located about 1,900 kilometres southeast of Tokyo. If successful, the mission will mark the world’s first attempt to continuously retrieve rare-earth-bearing seabed sediment from a depth of roughly six kilometres and lift it directly to a surface vessel.
The project comes at a time of heightened geopolitical tension over supply chains for critical minerals, which are essential for manufacturing electric vehicles, smartphones, wind turbines and advanced military equipment. China currently dominates global production and processing of rare earths, giving Beijing considerable leverage as trade and security frictions with Japan and Western nations intensify.
“After seven years of steady preparation, we can finally begin the confirmation tests. It’s deeply moving,” said Shoichi Ishii, head of the state-supported project, as the Chikyu departed under clear skies with Mount Fuji visible in the distance. “If this succeeds, it will be extremely significant for diversifying Japan’s procurement of rare-earth resources. Recovering minerals from six kilometres below the sea surface would also be a major technological breakthrough.”
The vessel, carrying around 130 crew members, engineers and researchers, is scheduled to return to port on February 14 after completing test operations near Minamitori Island, which lies within Japan’s exclusive economic zone.
Japan’s push into deep-sea mining has gained urgency following fresh export controls announced by China. Last week, Beijing banned shipments to Japan of certain items with both civilian and military applications, including some critical minerals. Media reports have suggested that broader restrictions on rare-earth exports to Japan may also be under consideration, although Chinese authorities have neither confirmed nor denied those claims.
Tokyo has condemned the dual-use export ban, warning that it could undermine stable trade relations, while stopping short of formally responding to reports of wider rare-earth curbs. Chinese state media, however, have indicated that tougher measures are being weighed.
Concerns over supply security are not new for Japan. In 2010, China temporarily halted rare-earth exports during a diplomatic dispute following a collision near contested islands in the East China Sea, exposing Japan’s vulnerability and jolting its manufacturing sector.
Since then, Japan has worked to reduce its reliance on Chinese supplies, cutting its dependence to about 60 per cent from roughly 90 per cent through investments in overseas projects, including partnerships with Australia’s Lynas Rare Earths, as well as promoting recycling and manufacturing technologies that require fewer rare earths.
Even so, analysts say Japan remains highly exposed, particularly for heavy rare earths used in high-performance magnets for electric and hybrid vehicle motors. For some of these materials, China remains the near-exclusive supplier.
“The fundamental solution is to be able to produce rare earths inside Japan,” said Takahide Kiuchi, executive economist at Nomura Research Institute. “If this new round of export controls ends up covering a wide range of rare earths, companies will again accelerate efforts to move away from China, but it won’t be easy.”
Japan has also built up undisclosed stockpiles of rare earths since the 2010 episode. At a recent New Year gathering of mining industry leaders, several executives said the country was better prepared to withstand potential disruptions than it was a decade ago, citing diversification efforts and reserves.
Nevertheless, officials warn against complacency. Kazumi Nishikawa, principal director of economic security at Japan’s trade ministry, said companies must be continually reminded to strengthen supply chain resilience.
“Sometimes an event happens and businesses react, but once it passes, they forget,” Nishikawa said on a recent podcast. “We have to maintain continuous efforts.”
The Minamitori Island project represents Japan’s first attempt to source rare earths domestically. Since 2018, the government has invested about 40 billion yen (roughly $250 million) in research and development related to the seabed deposits. While estimated reserves have not been disclosed and no commercial production target has been set, officials say a full-scale mining trial could be launched as early as February 2027 if the current tests prove successful.
Deep-sea mining has long been viewed as prohibitively expensive, but analysts say shifting geopolitics could alter the economics. “If supply disruptions from China persist and buyers are willing to accept higher prices, projects like this could become viable over time,” said Kotaro Shimizu, principal analyst at Mitsubishi UFJ Research and Consulting.
The operation has also drawn attention from China. During survey work near Minamitori Island last June, Chinese naval vessels were observed operating in nearby waters, according to Ishii.
“We felt a strong sense of crisis when such intimidating actions were taken,” he said. China has said its naval activities complied with international law and urged Japan to avoid “exaggerating threats.”
As competition over critical minerals intensifies, Japan’s deep-sea experiment underscores how resource security is becoming a central pillar of national strategy, blending technology, economics and geopolitics far beneath the ocean’s surface.
