Lead:

The Iranian Revolutionary Guard Corps announced Saturday the re-closure of the Strait of Hormuz, citing what Tehran describes as Washington's failure to honor the terms of a previously signed memorandum of understanding. The development has thrown the latest round of technical negotiations between the two sides — scheduled to convene in Burgenstok, Switzerland — into disarray, even as American envoy Steve Wittkoff departed for Geneva and an Iranian delegation arrived on Swiss soil late Saturday.

Details:

According to Al-Yaum, Iran's Mehr News Agency — citing the Khatam al-Anbiya joint military command — formally announced the re-closure of the strait, accusing the United States of violating the memorandum of understanding. The Iranian Revolutionary Guard Corps elaborated that the closure was a direct response to Washington's non-compliance, a position also relayed by Al-Watan, which reported that Tehran formally accused Washington of breaching the agreement.

Al-Jazirah reported that U.S. President Donald Trump, for his part, stated clearly that ships will face no transit fees in the Strait of Hormuz beyond the sixty-day window stipulated in the memorandum, adding that he remains optimistic that all outstanding issues with Iran can be resolved within that timeframe. Trump simultaneously signaled that a military option remained on the table should negotiations fail to produce a final deal, according to Al-Yaum.

Al-Yaum further reported that Pakistan — serving as a diplomatic intermediary between Washington and Tehran — announced the talks would formally open on Sunday. Pakistan's Interior Minister Mohsen Naqvi traveled to Tehran on Saturday as part of coordinated mediation efforts following the postponement. Newsd noted that Mohsen Rezaei, a member of Iran's Expediency Council, publicly warned that Iran's control over the Strait of Hormuz must not be weakened, framing the strait as a cornerstone of Iranian regional power.

On the American side, Al-Yaum noted the U.S. military stated it was maintaining heightened readiness in the wake of the closure announcement, while the Lebanese dimension added further complication: Al-Jazirah reported that Prime Minister Benjamin Netanyahu had instructed the Israeli military to halt operations in Lebanon, though without withdrawing from existing security zones — a development that may influence the broader negotiating atmosphere in Switzerland.

Watch For:

Whether Sunday's technical talks in Burgenstok proceed as announced by Pakistan or face a second postponement amid continued Israeli strikes in southern Lebanon that Iran has cited as grounds for the re-closure.

The durability of the sixty-day framework: Trump's public statements accept no transit fees after the deadline expires, but Tehran's willingness to remain bound by the memorandum is now openly in question.

The role of Pakistan as mediator: Naqvi's unscheduled visit to Tehran signals active back-channel pressure; his success or failure in stabilizing the process will be a key indicator of whether talks can survive the current impasse.