US-Iran complete first round of talks. But Trump's threat nearly threw them off course

High-stakes negotiations between the United States and Iran concluded their first round in Switzerland on Sunday, with mediators describing the talks as constructive despite a dramatic interruption triggered by fresh threats from US President Donald Trump.

The discussions, held at the Burgenstock resort overlooking Lake Lucerne, brought together senior representatives from Washington and Tehran in an effort to build on a recently signed framework agreement aimed at reducing regional tensions, reopening maritime routes and addressing long-standing disputes over Iran's nuclear programme. Qatar and Pakistan acted as key mediators during the talks.

The talks got off to a shaky start after Trump warned that the United States could take military action if Iran failed to curb the activities of allied groups in Lebanon and keep the Strait of Hormuz open. According to multiple reports, the remarks angered Iranian officials, who briefly walked out of the negotiations and refused to participate in a planned joint photo opportunity.

Despite the tensions, diplomatic efforts by Qatari and Pakistani mediators helped prevent a complete collapse of the talks. Iranian and American representatives eventually resumed discussions through indirect channels, allowing negotiations to continue.

At the conclusion of the first round, mediators announced that both sides had agreed on a roadmap aimed at reaching a broader agreement within 60 days. The proposed framework includes discussions on sanctions relief, maritime security in the Strait of Hormuz, regional stability and Iran's nuclear activities. Technical-level negotiations are expected to continue throughout the week.

Iranian Foreign Minister Abbas Araghchi described the outcome as "major progress," while US Vice President JD Vance said the discussions covered a range of issues, including nuclear concerns, regional security and efforts to prevent further escalation in Lebanon.

Among the measures reportedly discussed were the creation of a direct communication mechanism to avoid incidents in the Strait of Hormuz and a coordination framework designed to reduce the risk of conflict spilling across the region. Reports also suggested that Washington could consider temporary sanctions waivers if negotiations continue to advance.

The first round comes just days after the US and Iran reached a preliminary understanding intended to end months of confrontation and create a pathway for broader diplomatic engagement. However, analysts caution that the toughest issues—including the future of Iran's nuclear programme and long-term sanctions relief—remain unresolved.

For now, both sides appear willing to keep talking. Yet Sunday's brief walkout highlighted how quickly progress can be threatened by inflammatory rhetoric, underscoring the fragile nature of one of the world's most consequential diplomatic efforts.