US-Iran negotiations following 2025-2026 strikes on nuclear sites have centered on Iran's remaining stockpile of roughly 440 kg of uranium enriched to 60%, with portions potentially buried at Isfahan and other locations. Interim memoranda signed in June 2026 established a ceasefire extension, Strait of Hormuz access, and sanctions considerations while deferring final terms on the material to further talks, specifying IAEA-supervised on-site down-blending as the minimum option rather than physical transfer. Recent US sanctions on Iranian industries and statements from officials emphasizing verifiable reductions have sustained diplomatic pressure, yet Iranian positions favor in-country handling amid disputes over site access and inspections. Trader consensus reflects these procedural and political barriers, with the narrow window to year-end and lack of confirmed transfer mechanisms limiting prospects for US custody by December 31. Key near-term catalysts include any extension or conclusion of the negotiating period and IAEA developments.