By Wu Qiaoxi | 2026-06-18

Japan is developing a new autonomous underwater vehicle for deployment by fiscal year 2028, aiming to improve deep-sea survey efficiency and support future commercial extraction.

The program builds on Japan's recent success collecting rare earth-bearing sediment from approximately 6,000 meters below the surface.

Tokyo aims to begin commercial extraction of rare earth mud from the seabed near Minami-Torishima Island by around 2030. In February, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) research vessel Chikyu retrieved rare earth-rich sediment from a seafloor approximately 6,000 meters deep near the island, setting a world record for the deepest seabed rare earth collection.

JAMSTEC is developing a new unmanned deep-sea vehicle capable of both high-speed survey cruises and stationary hovering at depth, Japan's Sankei Shimbun reported. The system is designed to significantly improve resource survey efficiency.

The vehicle can dive at roughly a 60-degree angle, reaching its 6,000-meter operating depth in as little as 1.5 hours. Tokyo has set aside a five-year budget of approximately 8 billion JPY ($49.8 million) for developing it.

Chinese squeeze

Japan's concerns over rare earth supply disruptions have grown since Prime Minister Sanae Takaichi made remarks related to a "Taiwan contingency" last November. Beijing ratcheted up rare earth export restrictions starting in January in retaliation. Chinese rare earth exports to Japan fell more than 80% year on year in both March and April, trade data show. China produces roughly 70% of the world's rare earths and controls about 90% of global processing and refining capacity.

Major Japanese magnet maker Shin-Etsu Chemical has stopped accepting new orders for dysprosium-containing magnets, according to a Western customer who spoke on condition of anonymity. The company declined to comment. Reuters reported the company is planning a new refinery to shore up supply stability, with investment expected to exceed 35 billion JPY ($217.5 million) and roughly half covered by government subsidies.

The supply disruption extends beyond rare earths. Chinese exports of tungsten to Japan fell to near zero between February and April, Kyodo News reported. Tungsten is widely used in automotive and precision manufacturing, and Japanese companies have had to seek alternative suppliers as prices surged to more than three times their previous levels.

Supply shock

Japan faced a similar rare earth shock in 2010 following a Sino-Japanese multi-ship collision near the Senkaku Islands. China effectively halted rare earth exports to Japan, disrupting high-tech and automotive supply chains.

Japan has reduced its vulnerability since the 2010 rare earth shock by combining supply diversification, substitute-material research and "effective action under international trade rules," Kunihiko Shinoda, a professor at Japan's National Graduate Institute for Policy Studies, wrote in the East Asian Quarterly in March. China's share of Japan's rare earth imports fell from about 90% in 2010 to below 60% by 2020.

Shinoda noted that Japan's 2022 Economic Security Promotion Act designated critical minerals as "specified critical goods" and set 2030 quantitative targets for lithium, nickel, cobalt, graphite and rare earths, with concrete results beginning to emerge.

Japan's push to extract rare earths near Minami-Torishima reflects concern over intensifying geo-economic competition in the Indo-Pacific and the need to build a strategic reserve, Takahiro Kamisuna, a Japan scholar at the London-based International Institute for Strategic Studies, said.

Such reserves could strengthen Japan's economic resilience and blunt China's ability to "weaponize its control over rare earth processing," he said.

The project should therefore be seen as "diplomatic and economic statecraft" rather than as a conventional commercial mining plan, Kamisuna said.

Diversification drive

Japan is pursuing overseas partnerships to diversify supply sources. Tokyo plans to dispatch a delegation to Greenland this summer to assess rare earth extraction potential, the Nikkei reported.

Greenland holds an estimated 1.5 million tons of rare earth reserves, the world's eighth largest deposit, making it a potential alternative source as Japan seeks to reduce reliance on Chinese supplies. No rare earth extraction has yet taken place on the island.

The issue has moved onto the G7 agenda. Leaders agreed on June 17 to reduce dependence on any single non-G7 supplier of rare earths and permanent magnets to below 60% by 2030. The bloc committed to coordinating stockpiles and supply chain monitoring to reduce future disruptions.