# The United States and Japan plan the world's deepest undersea mine to break China's hold on heavy rare earths

Recovery from about 6,000 metres near Minamitorishima would cost roughly three times Chinese land-based extraction, with full-scale test excavation planned for February 2027.

- Published: 2026-08-13T05:22:48.900Z
- Canonical: https://polylog.news/2026-08-13/the-united-states-and-japan-plan-the-world-s-deepest-underse
- Publisher: Polylog (Global desk)
- Section: geopolitics
- Sources: [The Japan Times](https://www.japantimes.co.jp/news/2026/08/13/japan/us-japan-undersea-mine-china/), [South China Morning Post](https://www.scmp.com/news/china/diplomacy/article/3363853/us-china-rivalry-takes-flight-over-scramble-contracts-ethiopias-bishoftu-airport?utm_source=rss_feed)

Japan and the United States intend to recover rare-earth-bearing mud from roughly 6,000 metres below the sea near Minamitorishima, a small Japanese island about 1,900 kilometres southeast of Tokyo, in what would be the deepest mining operation ever attempted. [The Japan Times reported](https://www.japantimes.co.jp/news/2026/08/13/japan/us-japan-undersea-mine-china/) a joint statement describing deposits that could meet centuries of industrial demand. Japan has spent about 40 billion yen since 2018 and estimates a further 340 billion yen, close to $2.1 billion, to build a domestic extraction and refining chain.

The technical case depends on composition rather than volume. More than half the recovered material consists of medium and heavy rare earths including dysprosium, yttrium and gadolinium, the categories China dominates most completely. The research drillship Chikyu [recovered mud from about 5,700 metres in February](https://www.aljazeera.com/news/2026/2/2/japan-deep-sea-hunt-finds-rare-earths-as-it-seeks-to-cut-reliance-on-china), demonstrating continuous pumping, and a full-scale test excavation is planned for February 2027. Water pressure at target depth is roughly 600 times that at the surface, and offshore oil drilling operates at about half this depth.

The economics are unfavourable and deliberately so. Bloomberg reported the operation would produce at roughly three times the cost of Chinese land-based extraction and would need billions of dollars over more than a decade, [according to its account carried by Mining.com](https://www.mining.com/web/us-japan-plan-worlds-deepest-undersea-mine-to-challenge-china/). China's export controls give the project its rationale. Beijing added ten United States entities including MP Materials to its control list in June and fourteen European Union firms in July, and a second wave covering holmium, erbium, thulium, europium and ytterbium takes effect on 10 November.

The same competition is occurring in infrastructure contracts. The [South China Morning Post reported](https://www.scmp.com/news/china/diplomacy/article/3363853/us-china-rivalry-takes-flight-over-scramble-contracts-ethiopias-bishoftu-airport?utm_source=rss_feed) that Ethiopian Airlines' $12.5 billion Bishoftu International Airport project has become a contest between American and Chinese firms for construction and financing work, a pattern repeated across African infrastructure.

## What this means

Governments are now willing to fund resource extraction at three times the market cost to remove a single supplier's leverage, which means the price of heavy rare earths in Western supply chains will be set by policy rather than by the cheapest producer. Defence contractors, electric-vehicle makers and wind-turbine manufacturers gain security of supply and lose the low input cost they enjoyed. China loses that leverage, but only after 2027 at the earliest, and its November expansion of export controls arrives well before any of this material reaches a factory.

## What to watch

- Whether the February 2027 test excavation succeeds at full scale. A failure at 6,000 metres would push Western heavy rare-earth independence out by years and strengthen China's negotiating position.
- Whether China's second wave of export controls takes effect on 10 November as scheduled or is suspended again as part of a trade truce, which would show whether Beijing treats the controls as leverage or as permanent policy.
- Who wins the Bishoftu airport contracts in Ethiopia, since large African infrastructure awards indicate which financing model Global South governments find more attractive.