Vice President JD Vance meets with Pakistan’s Prime Minister Shehbaz Sharif at the Bürgenstock Resort near Lucerne, Switzerland, June 21, 2026. The U.S. and Iran have made progress in post-deal peace talks, though ongoing threats and hardline positions risk derailing negotiations before they begin in earnest. (Nathan Howard/Pool Photo via AP)
The U.S. and Iran might have cleared the first hurdle in postwar negotiations, with both sides reporting progress after the opening round of talks.
But neither appears willing to back down from combative rhetoric, suggesting the road to lasting peace could be a long one.
Following 18 hours of talks in Switzerland, U.S. Vice President JD Vance said Monday that it had been a “very, very good day,” citing the establishment of mechanisms to prevent regional military escalation, safeguard commercial shipping and facilitate further technical negotiations.
There were also early signs of implementation. Treasury Secretary Scott Bessent said the U.S. had issued a 60-day license authorizing the production, delivery and sale of Iranian oil as part of the framework reached in Switzerland.
Iranian Foreign Minister Seyed Abbas Araghchi also described the talks as having achieved “major progress.”
The positive assessments came as leaders in Tehran and Washington continued to trade verbal barbs, highlighting the challenges facing a 60-day ceasefire process meant to produce a longer-term agreement on Iran’s nuclear program and U.S. sanctions.
President Donald Trump, who last week suggested that he would resume strikes if Iran did not “behave” during talks, escalated his rhetoric Sunday by warning that Iranian President Masoud Pezeshkian “better watch his mouth.”
“He better shape up. Or we’ll take over the rest of the country,” Trump told Fox News, without elaborating.
That prompted a response from Mohammad Bagher Ghalibaf, Iran’s parliamentary speaker, who said on social media that U.S. leaders had “better watch their words” and that Iranian armed forces were ready to respond.
The bilateral memorandum of understanding signed last week was widely celebrated for putting an end to a war that had lasted more than 100 days, killed 13 U.S. service members and disrupted fuel supplies around the world.
Yet the ceasefire has already faced early tests. The first round of negotiations briefly appeared to be in jeopardy on Saturday after Iran said it had re-closed the Strait of Hormuz in protest of Israel’s continued military campaign in Lebanon.
U.S. Central Command quickly refuted that claim, saying that Iran did not control the strait and traffic continued to flow. It’s not clear whether Iran took any action to stop ships.
The U.K. Maritime Trade Operations Centre, a British military-run maritime security monitoring center for commercial shipping, did not report any incidents in the strait over the weekend, though traffic appeared to drop significantly.
Maritime tracker Windward said only 12 vessels transited the strait on Sunday, down from more than 21 the day before. That’s far below the prewar average of more than 100 ships a day.
Trump also issued what appeared to be a threat against Iranian officials involved in any effort to close the strait, telling Fox News: “You close it, you won’t have a country” and “you won’t even make it back to your f---ing country.”
The high-level talks proceeded despite the dispute. Iranian state media reported that Tehran’s negotiators had held 18 hours of “intensive dialogue and consultations.” Technical talks are set to continue this week, according to mediators.
Vance said Monday that Iran agreed to invite international nuclear inspectors back to the country, a move he said marked a “major milestone (in) ending a nuclear weapons program in Iran.” Iran has not confirmed the invitation.
Instead, Iranian state media reported that much of the talks centered on Lebanon, where fighting between Israeli forces and the Iran-backed Hezbollah militant group has emerged as one of the biggest threats to the ceasefire.
Trump has expressed frustration with Israeli Prime Minister Benjamin Netanyahu, especially as continued Israel-Hezbollah hostilities have hardened Tehran’s negotiating position.
Trump on Sunday also turned his ire toward Hezbollah, saying in a post to Truth Social that Iran must “immediately stop their highly paid PROXIES in Lebanon from causing trouble.”
“If they don’t, we’ll hit Iran very hard again, just like we did last week, only harder!!!” he wrote.
A resumption of full-scale war would carry significant risks. The United States has sustained considerable damage to its bases in the Middle East and has expended large quantities of some of its key munitions.
Renewed fighting would also further threaten global energy supplies. Speaking on the sidelines of the G7 summit in France last week, Trump suggested that without a deal, global oil reserves would have run out in just four weeks.
Iran has also suffered heavy military losses, including the destruction of much of its air defense network and the deaths of several top leaders, including Supreme Leader Ayatollah Ali Khamenei.
