US Secretary Rubio Warns Hormuz Tolls ‘Would Spread like a Contagion’

US Secretary of State Marco Rubio on Thursday warned that Iranian plans to impose tolls on ships passing through the Strait of Hormuz would "spread like a contagion" to other international waterways, risking total chaos, as he sought to reassure Gulf allies that any deal with Tehran would not undermine their security.

Speaking at a Gulf Cooperation Council (GCC) meeting in Bahrain, Rubio said the principle that international waterways belong to no single nation was foundational to global order. "If in fact we accepted that you can charge money to use an international waterway because it happens to be near your territorial space, well then this will spread throughout the world like a contagion," he told the gathering, according to AFP.

Rubio's warning came hours after Iran's Revolutionary Guards Corps (IRGC) threatened to "deal with" any vessels crossing the Strait without authorisation, declaring that the only safe route was one designated by Tehran, AFP reported. The Guards also denounced a new route promoted by Oman and the International Maritime Organisation, calling it "unacceptable and extremely dangerous".

According to Reuters, Rubio is on a regional tour to sell the Trump administration's preliminary interim deal with Iran to sceptical Gulf Arab states, which were targeted by Tehran's missiles and drones during the recent war and saw their oil shipments effectively blocked by an Iranian blockade of the waterway. Rubio has insisted that Washington would remain "completely aligned" with its Gulf partners and would not do anything to undermine their security or prosperity.

Oman's foreign minister, Badr Albusaidi, moved to allay fears, saying that "future arrangements regarding the Strait do not entail the imposition of any transit fees", after Muscat and Tehran had earlier discussed possible service costs. Bahrain's top diplomat welcomed Oman's corridor for safe passage, but the IRGC rejected any route not coordinated with Iran.

The stand-off over the Strait, through which about a fifth of the world's oil passes, has added fresh friction to US-Iran negotiations aimed at finalising a permanent ceasefire. While Rubio said Washington was open to a "real, enduring" peace, he stressed that the US would not strike a deal "at any price" that compromised Gulf security, AFP reported from the Bahrain meeting.

Technical talks between Washington and Tehran are expected to resume next week in Switzerland, according to Pakistani officials, as both sides work to implement the memorandum of understanding signed last week. However, the IRGC's stance and Rubio's contagion warning underscore the fragility of the truce, with oil prices extending declines on Thursday to near pre-war levels amid rising supply expectations from the Middle East.

The US Senate, meanwhile, rejected a war powers resolution after President Donald Trump berated Republican lawmakers, signalling continued domestic political friction over the conflict.