The two sides agreed to identify joint projects across the mining, smelting and processing chain for rare earth elements essential to advanced manufacturing, clean energy and defence.

Speaking in the Diet on Thursday, Takaichi said, “It is important for both Japan and the United States to secure diverse procurement methods. We are considering specific ways to proceed with cooperation.”

Takaichi has long been a proponent of exploiting Japan’s reserves of minerals and rare earth elements, even though their location at the bottom of the Pacific Ocean has made them relatively difficult to access.

And while Tokyo recognises that it will be costly to develop the technologies to extract rare earths – such as dysprosium, terbium, neodymium and yttrium – from the seabed, it is also acutely aware that it cannot rely on other producers to ensure an uninterrupted supply of the materials that its companies require.