U.S. and Iranian negotiators pushed deep into Sunday night at the Lake Lucerne Summit in Switzerland, working to launch a 60-day process toward a new nuclear agreement. The nearly uninterrupted sessions place both delegations on record as still engaged despite material differences — and they ran alongside a live dispute over the Strait of Hormuz after Tehran said Saturday it was closing the waterway in response to Israeli ceasefire violations in Lebanon.
Who Is at the Table and What They Covered
Vice President JD Vance is leading the U.S. effort, joined by White House envoys Steve Witkoff and Jared Kushner. Mediators from Pakistan and Qatar are active participants — a quartet configuration that gives both Washington and Tehran additional back-channels to work through. According to a U.S. diplomat, discussions covered "all elements of the nuclear deal," as well as the memorandum of understanding already in place and how to align all parties on its implementation. The two sides also agreed on a framework for continuing engagement between political leaders and technical teams once the Lake Lucerne round closes.
The Hormuz Thread
The Strait of Hormuz featured explicitly in the talks. Iran's claim Saturday that it was shutting the waterway — one of the world's most critical energy transit corridors — created a direct test of how much diplomatic ground the Switzerland sessions had actually prepared. The U.S. diplomat said the parties discussed the strait and Iran's statements about potentially closing it. "We made clear we want to ensure it remains fully open. We made good progress on that front," the diplomat said. Any sustained closure of the Hormuz passage would ripple immediately into crude routing and pricing, making the deconfliction work at Lake Lucerne operationally significant well beyond the nuclear file.
Lebanon Ceasefire as a Parallel Track
One underappreciated element of the Lake Lucerne agenda is Lebanon. The U.S. diplomat identified "deconfliction mechanisms in Lebanon and enforcing the ceasefire" as a specific topic, pointing to ongoing clashes between Hezbollah and Israeli forces in southern Lebanon as the live friction the talks are trying to contain. That Iran's Hormuz statement was itself framed as a response to Israeli ceasefire violations illustrates how tightly the nuclear file, the Lebanon ceasefire, and the Hormuz question are knotted together in these negotiations.
What Comes Next
High-level political talks are expected to conclude Monday. Technical teams, however, are likely to remain in Switzerland to press forward on the implementation details. The U.S. diplomat summarized the mood across all four delegations — U.S., Iran, Pakistan, and Qatar — as positive: "The mediators are helping both sides work through things. We feel this initial round of talks is setting us up for trust building going forward." Whether the 60-day framework holds depends on what the technical teams produce in the days after the principals leave Lake Lucerne.