US and Japan Move to Strengthen Deep-Sea Mining Ties through Memorandum of Cooperation
Client Alert | April 13, 2026
Gibson Dunn’s Geopolitical Strategy and International Law team—together with our International Arbitration, and ESG Risk Advisory teams—can help investors understand and navigate the multi-dimensional legal and regulatory risks of deep-sea mining.
On 19 March 2026, the United States and Japan signed a Memorandum of Cooperation Regarding Deep-Sea Mineral Resource Development (the MOC), formalizing their collaboration on deep-sea mining efforts.[1] Pursuant to the MOC, the countries have agreed to share research and cooperate on the development of deep-sea science and mineral extraction.
This MOC is the latest deep-sea mining sector development in the United States—and in the sector more broadly, which is evolving at pace.[2] The MOC follows a joint statement of cooperation on deep-sea mining between the United States and the Cook Islands, published in August 2025.[3]
The MOC
The three-page MOC was signed following recent talks between President Trump and Prime Minister Sanae Takaichi in Washington D.C. The MOC establishes a framework for bilateral cooperation in deep-sea mining, though it is not legally binding.[4]
After signing, the MOC was presented to the International Seabed Authority (ISA)—the intergovernmental body that regulates the ocean floor in international waters established under the United Nations Convention on the Law of the Sea (UNCLOS).[5]
A central component of the MOC is the creation of a Japan-U.S. Working Group on Deep-Sea Mineral Resource Development (the Working Group), which aims to “facilitate bilateral cooperation in science and technology, and support efforts to accelerate deep-sea mineral resource development”.[6] The MOC tasks the Working Group with various responsibilities, including information sharing on deep-sea science and mining projects as well as related technology.[7] This information sharing includes insights from Japan’s recent rare-earth muds project near Minamitorishima Island, the easternmost territory belonging to Japan, which is believed to have significant potential for the long-term supply of certain critical minerals.[8]
The MOC also encourages engagement with US and Japanese private sector actors to “obtain input, discuss regulatory approaches and best practices, share information, and facilitate partnerships to inform research priorities and support development of new economic opportunities”.[9]
Broader US-Japan Partnership on Critical Minerals
The deep-sea mining partnership between the United States and Japan is not the only area of cooperation between the States in the mining context—they are increasingly working together in the critical-minerals sphere. In October 2025, they announced the United States-Japan Framework For Securing the Supply of Critical Minerals and Rare Earths through Mining and Processing (the Framework), a plan outlining collaborative policies within this sphere. The Framework includes policies that focus on joint investment in mining and processing, permitting, and supply chain coordination.[10]
On the same day the MOC was signed, the United States and Japan also expanded their cooperation on critical minerals and rare earths supply chains with the enactment of the U.S.-Japan Action Plan on Critical Minerals (the Action Plan).[11] Under the Action Plan, both governments have agreed to discuss and develop coordinated trade policies and mechanisms relating to critical minerals, with the end goals of addressing vulnerabilities in global supply chains and protecting downstream industries dependent on critical minerals imports.[12]
Comment
This latest development demonstrates the continued prioritization by the Trump Administration of developing alliances to pursue deep-sea mining, and doing so outside of the UNCLOS framework—frustrated, as we have reported previously, by the pace of progress in the development of an international regulatory framework by the ISA. Aside from governance complexities, there are significant concerns about the potential impact of deep-sea mining on the environment, which has prompted many States to call for a moratorium on deep-sea mining.
We will continue to monitor and report on developments in the deep-sea mining space.
Gibson Dunn’s Geopolitical Strategy and International Law team—together with our International Arbitration, and ESG Risk Advisory teams—can help investors understand and navigate the multi-dimensional legal and regulatory risks of deep-sea mining. Please do not hesitate to reach out.
[1] See Memorandum of Cooperation Regarding Deep-Sea Mineral Resource Development Between the Ministry of Economy, Trade, and Industry of Japan and the Department of Commerce of the United States of America, 19 March 2026, available at: https://www.mofa.go.jp/files/100998735.pdf.
[2] See Gibson Dunn, US Moves to Reduce Deep-Sea Mining Permit Times Under New NOAA Rule, 12 February 2026, available at: https://www.gibsondunn.com/us-moves-to-reduce-deep-sea-mining-permit-times-under-new-noaa-rule/; Gibson Dunn, Mining of the Deep-Sea—The Trump Administration’s Executive Order, the International Law Framework and Implications for Investors, 21 July 2025, available at: https://www.gibsondunn.com/mining-of-the-deep-sea-trump-administration-executive-order-international-law-framework-and-implications-for-investors/.
[3] See U.S. Department of State, Joint Statement on U.S.-Cook Islands Cooperation on Seabed Mineral Resources, 5 August 2025, available at: https://www.state.gov/releases/office-of-the-spokesperson/2025/08/joint-statement-on-u-s-cook-islands-cooperation-on-seabed-mineral-resources.
[4] See New York Times, Japan and the U.S. Agree to Team Up on Seabed Mining, 27 March 2028, available at: https://www.nytimes.com/2026/03/27/climate/japan-united-states-seabed-mining.html.
[5] See New York Times, Japan and the U.S. Agree to Team Up on Seabed Mining, 27 March 2028, available at: https://www.state.gov/releases/office-of-the-spokesperson/2025/08/joint-statement-on-u-s-cook-islands-cooperation-on-seabed-mineral-resources.
[6] Memorandum of Cooperation Regarding Deep-Sea Mineral Resource Development Between the Ministry of Economy, Trade, and Industry of Japan and the Department of Commerce of the United States of America, 19 March 2026, available at: https://www.mofa.go.jp/files/100998735.pdf.
[7] See Memorandum of Cooperation Regarding Deep-Sea Mineral Resource Development Between the Ministry of Economy, Trade, and Industry of Japan and the Department of Commerce of the United States of America, 19 March 2026, available at: https://www.mofa.go.jp/files/100998735.pdf.
[8] See Mining Weekly, US-Japan deal targets supply chains, backs deep-sea minerals push, 20 March 2026, available at: https://www.miningweekly.com/article/us-japan-deal-targets-supply-chains-backs-deep-sea-minerals-push-2026-03-20.
[9] Memorandum of Cooperation Regarding Deep-Sea Mineral Resource Development Between the Ministry of Economy, Trade, and Industry of Japan and the Department of Commerce of the United States of America, 19 March 2026, available at: https://www.mofa.go.jp/files/100998735.pdf.
[10] See The White House, United States-Japan Framework For Securing the Supply of Critical Minerals and Rare Earths through Mining and Processing, 27 October 2025, available at: https://www.whitehouse.gov/briefings-statements/2025/10/united-states-japan-framework-for-securing-the-supply-of-critical-minerals-and-rare-earths-through-mining-and-processing/.
[11] See Office of the United States Trade Representative, Ambassador Jamieson Greer Announces U.S.-Japan Action Plan on Critical Minerals, 19 March 2026, available at: https://ustr.gov/about/policy-offices/press-office/press-releases/2026/march/ambassador-jamieson-greer-announces-us-japan-action-plan-critical-minerals.
[12] See Office of the United States Trade Representative, Ambassador Jamieson Greer Announces U.S.-Japan Action Plan on Critical Minerals, 19 March 2026, available at: https://ustr.gov/about/policy-offices/press-office/press-releases/2026/march/ambassador-jamieson-greer-announces-us-japan-action-plan-critical-minerals.
Gibson Dunn’s lawyers are available to assist in addressing any questions you may have regarding these issues. Please contact the Gibson Dunn lawyer with whom you usually work, the authors, or any leader or member of the firm’s International Arbitration or Geopolitical Strategy & International Law practice groups:
Robert Spano – Co-Chair, Geopolitical Strategy & International Law Group,
London/Paris (+33 1 56 43 13 00, rspano@gibsondunn.com)
Rahim Moloo – Co-Chair, Geopolitical Strategy & International Law Group,
New York (+1 212.351.2413, rmoloo@gibsondunn.com)
Patrick W. Pearsall – Co-Chair, Geopolitical Strategy & International Law Group,
Washington, D.C. (+1 202.955.8516, ppearsall@gibsondunn.com)
Lindsey D. Schmidt – New York (+1 212.351.5395, lschmidt@gibsondunn.com)
Ceyda Knoebel – London (+44 20 7071 4243, cknoebel@gibsondunn.com)
Stephanie Collins – London (+44 20 7071 4216, scollins@gibsondunn.com)
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