US forces launched waves of attacks for the third successive night after Iran said on Saturday it was closing the strait, prompting US President Donald Trump to reinstate a blockade of Iranian shipping and propose charging a 20 per cent fee to guard the vital waterway.
The strikes have increased doubts that an interim deal agreed in June will lead to a permanent halt in a more than four-month-old war that has disrupted global energy supplies and raised fears of a rise in inflation across the world.
The war has proved unpopular in the US, where petrol prices have risen since the start of the war, with congressional elections looming in November.
Oil prices rose again on Tuesday, with Brent crude futures hitting more than $US86 a barrel, but were still well below the peak since the war began.
The US and Israel attacked Iran on February 28, and Iran attacked Israel and Gulf states that host US bases.
The war also reignited conflict between Israel and Hezbollah militants in Lebanon.
It killed thousands and displaced millions, the vast majority in Iran and Lebanon.
Lebanon and Israel were set to resume talks on Tuesday in Rome, with Beirut seeking progress towards securing an Israeli withdrawal from south Lebanon under a US-brokered deal.
In the latest strikes in the wider war, Iran's Islamic Revolutionary Guard Corps said a US air base in Jordan had been targeted with ballistic missiles.
Jordan's armed forces said they shot down four missiles, according to a state news agency.
The IRGC called on Jordan to dismantle American bases in the kingdom.
Iranian media reported US strikes on a number of cities and said four people had been wounded and rescue operations were under way.
Hostilities have intensified since Iran said on Saturday it had closed the Strait of Hormuz after firing a warning shot that struck a vessel travelling on what it said was an unauthorised route.
Trump said on Monday on Truth Social that the strait was open and would remain open, with or without Iran.
"We are reinstating THE IRANIAN BLOCKADE," Trump said, announcing that the US would charge a 20 per cent fee on all cargo shipped through it.
Iran has also sought to establish its control over the strait and a system for collecting fees, warning vessels not to sail without its authorisation.
Iran's military said the US had no role in determining the future of the waterway, while Foreign Minister Abbas Araqchi wrote on X that Tehran was the guardian of the strait and would remain so "forever".
The UN shipping agency said it opposed fees such as the US's proposed 20 per cent levy and there was no legal basis for introducing mandatory tolls on strait transits.
The United Arab Emirates defence ministry said on Monday that Iranian cruise missiles struck two Emirati oil tankers while transiting the southern lane of the strait in Omani territorial waters.
One Indian crew member was killed and eight others were wounded, the ministry said on Tuesday.
The IRGC said two "offending" supertankers had been hit and disabled in the strait after ignoring repeated warnings and turning off navigation systems.
It accused the US of "inciting vessels to use an illegal route" and warned that co-operation with the "aggressor enemy" would result in damage, delays in reopening the waterway and a global energy crisis.
The US Navy-led Joint Maritime Information Centre said a blockade of Iran would take effect on Tuesday and apply to all vessel traffic regardless of flag, covering the entire Iranian coastline including ports and oil terminals.
