U.S.-Iran Nuclear Talks Collapse 24 Hours After Swiss Confirmation

Switzerland confirmed U.S.-Iran nuclear negotiations at Bürgenstock on June 18, then both parties canceled within 24 hours on June 19. The abrupt collapse removed the most visible diplomatic channel since 2015, when the JCPOA fell apart. Neither side disclosed the specific sticking point—whether nuclear enrichment limits, sanctions sequencing, or agreement permanence triggered the breakdown. Whether back-channel contacts through Oman or Qatar remain active will determine if talks resume or stall indefinitely.