The policy brief emphasizes the potential for strengthened relations between the United States and South Korea through pragmatic cooperation in clean energy technologies. Both nations, with advanced industrial economies, are committed to reducing greenhouse gas emissions and enhancing energy security. Recommendations include sharing technological expertise, aligning market rules, investing in supply chains, and promoting research on clean hydrogen and advanced nuclear power. While both countries have made progress in clean energy investment and collaboration, challenges like regulatory barriers, infrastructure deficiencies, and market dominance by China persist. The brief suggests adopting pragmatic policies, expanding battery supply chain resilience, and investing in clean hydrogen research and development. Furthermore, joint commitment to nuclear power expansion can help reduce costs, investor uncertainty, and supply chain risks, ensuring reliable baseload electricity. By working together on clean energy solutions, the US and South Korea can advance their climate goals and enhance mutual economic and energy security.