US-Iran diplomacy remains stalled after a June 2026 memorandum of understanding ended direct conflict without resolving the fate of Iran’s roughly 440 kg stockpile of uranium enriched to 60 percent. US officials, including Vice President JD Vance in early October statements, have conditioned any final agreement on verifiable reductions in Iranian enrichment capacity, while Tehran maintains the material must remain inside the country and has blocked IAEA access to bombed sites at Isfahan and Natanz. Much of the stockpile is believed buried under rubble from prior US-Israeli strikes, with Iran denying any transfer commitment. These factors have kept trader-implied probabilities low for US possession by late 2026, reflecting persistent gaps over verification, downblending, or physical removal under international oversight.