A tenuous ceasefire between the United States and Iran remained in place on Saturday, but came under mounting strain as Iran's Islamic Revolutionary Guard Corps (IRGC) threatened to strike American bases and warships in the Middle East if Iranian oil tankers or commercial vessels were attacked again. The warning came a day after US fighter jets fired on and disabled two Iranian-flagged tankers in the Gulf of Oman, which Washington said were attempting to breach its naval blockade of Iran's ports — a blockade imposed on 13 April in response to Iran's near-total closure of the Strait of Hormuz, the narrow waterway at the mouth of the Persian Gulf through which roughly a fifth of the world's oil passes. Iranian military officials said their navy had already responded to Friday's strikes with its own attacks before calm was restored. On Sunday morning, a separate incident was reported when a ship caught fire after being struck by an unknown projectile roughly 43 kilometres north-east of Doha, Qatar's capital, according to the UK Maritime Trade Operations centre.
Diplomacy continued in parallel with the skirmishes. The US and Iran, whose conflict began on 28 February with US-Israeli strikes on Iran, agreed to a Pakistani-brokered temporary truce on 8 April. Washington has since sent Tehran — via Pakistani mediators — a proposal to extend that ceasefire and establish a framework for broader peace talks, reportedly including a freeze on Iranian uranium enrichment in exchange for sanctions relief and the release of frozen Iranian assets. President Donald Trump said on Friday he expected Iran's response "supposedly tonight", and reiterated his expectation on Saturday to French broadcaster LCI. Iran's foreign ministry said the proposal remained "under review". Iranian Foreign Minister Abbas Araghchi, in a call with his Turkish counterpart, questioned Washington's sincerity, citing what he called repeated US violations of the ceasefire. Pakistani Prime Minister Shehbaz Sharif said his country was engaged with both sides "day and night". US Secretary of State Marco Rubio met Qatar's Prime Minister and Foreign Minister Sheikh Mohammed bin Abdulrahman Al Thani, a key intermediary, to discuss support for the Pakistani-led mediation effort, and the meeting also included US envoy Steve Witkoff.
A number of other actors are also shaping the diplomatic landscape. Russian President Vladimir Putin indicated that Moscow remains willing to store Iranian enriched uranium — as it did under the 2015 nuclear agreement — as part of a potential settlement, and said all sides had initially agreed to this before Washington hardened its position. Russia and Saudi Arabia jointly called for a "sustainable, long-term" diplomatic solution. A CIA assessment, first reported by the Washington Post, reportedly suggested Iran could withstand the US port blockade for roughly another four months, though a senior intelligence official disputed that characterisation, arguing the blockade was inflicting "real, compounding damage" on Iran's economy. Separately, Bahrain — the small Persian Gulf island nation that hosts the US Navy's Fifth Fleet regional headquarters — announced the arrest of 41 people it alleged were linked to the IRGC and had been collecting funds to send to Iran.
A parallel front in Lebanon also remained volatile. Israel carried out strikes killing at least 24 people across southern Lebanon on Saturday, including raids on a highway south of Beirut well outside Hezbollah's traditional strongholds. The attacks were among the most intense since a three-week-old ceasefire between Israel and Hezbollah — the Iran-backed Lebanese militant group — came into effect. Hezbollah said it responded with drone and rocket strikes on Israeli military targets, wounding at least three Israeli army reservists. The flare-up comes as Lebanon and Israel are due to hold direct negotiations in Washington the following week, which Hezbollah has publicly opposed. On the broader question of Iran's leadership, the country's new Supreme Leader Mojtaba Khamenei — son of Ayatollah Ali Khamenei, who was killed at the start of the war — has not been seen publicly since the conflict began, though an Iranian official said he was in "complete health" and recovering from injuries sustained in the opening attacks.