Where will the next US-Iran senior diplomatic meeting take place...?

On June 22, the first round of U.S.-Iran diplomatic talks in Switzerland concluded, with mediators reporting progress toward a roadmap for a final deal and follow-on technical talks expected to continue (see: https://www.aljazeera.com/news/2026/6/22/us-iran-agree-on-roadmap-towards-final-deal-in-switzerland-talks). This market will resolve according to the country in which the next direct or indirect senior-level diplomatic meeting between the United States and Iran begins by December 31, 2026, 11:59 PM ET. A diplomatic meeting occurs when representatives of both listed countries who are acting in an official capacity and are authorized to engage in diplomacy on behalf of their respective governments or governing authorities deliberately meet for the purpose of diplomacy or negotiation. A qualifying meeting need not result in any agreement, joint statement, or further engagement. A diplomatic meeting is senior-level if each listed entity is represented by a head of state, a head of government, or a vice president; a foreign minister; a minister of cabinet rank; the secretary or head of a national security council; the presiding officer of a national legislature; a special envoy; or another individual designated by the head of state or head of government to conduct diplomatic negotiations on their behalf. Individuals authorized only for technical, implementation, monitoring, staff-level, preparatory, or working-group-level talks will not be considered designated to conduct diplomatic negotiations on behalf of the head of state or head of government. This definition includes, but is not limited to, all of the following individuals: for the United States, Donald Trump, JD Vance, Marco Rubio, Scott Bessent, Steve Witkoff and Jared Kushner; and for Iran, Mojtaba Khamenei, Masoud Pezeshkian, Abbas Araghchi and Mohammad Bagher Ghalibaf. In each case, a qualifying representative must participate in the meeting. A direct meeting refers to a diplomatic meeting where the representatives of both countries directly interact with each other in person. Meetings conducted through translators qualify, provided direct, face-to-face communication occurs. An indirect meeting refers to a meeting conducted indirectly through designated mediators or facilitators. A qualifying indirect meeting must meet both of the following criteria (i) the designated intermediaries act with the knowledge and authorization of both entities; (ii) representatives of both entities are physicall