The US insists the Strait of Hormuz is open, despite Iran saying it has closed the waterway amid renewed strikes.
Hostilities, which flared up again this week, continued on Saturday after the US said it had struck more than 140 targets across Iran.
The attacks were a response to Iranian forces hitting a ship passing through the strait, which it said was using an unapproved route.
Iran has been trying to assert control over the waterway, and early on Sunday said it was closed until further notice.
It said it had hit a US base in Jordan, while the United Arab Emirates (UAE), Qatar, Kuwait, Oman and Bahrain all said they had responded to missiles and drones from Iran.
The BBC has approached US Central Command for comment on the attack in Jordan.
Qatar, a mediator in ceasefire talks, had not been attacked since April, while the UAE had not been attacked since May.
On Sunday afternoon, Iran’s IRNA news agency said missiles were launched by the “enemy” towards Qeshm Island – a strategically important island in the Gulf, home to an important IRGC base.
The renewed fire has put in jeopardy an interim ceasefire agreement signed last month, which aimed to reopen the Strait and eventually bring a permanent end to the conflict.
Earlier this week, US President Donald Trump declared the Iranian attacks meant the ceasefire was over, while Iran’s Foreign Minister Abbas Araghchi accused the US of violating the deal.
However, Trump said talks would still continue and mediators were trying to revive the process.
US media reported that Iran told American officials attacks on tankers earlier this week were a mistake and blamed a rogue internal group.
The latest hostilities were sparked after the IRGC said it had fired a naval cruise missile at a vessel that was attempting to sail along an unapproved route.
US Central Command (Centcom) said the IRGC “blatantly attacked” a Cyprus-flagged vessel which was “unable to continue its journey” due to damage to the engine room.
A crew member from the MV GFS Galaxy ship was missing, it added.
The UK’s Maritime Trade Operations (UKMTO) said it had been informed by military authorities that the crew of the vessel were forced to abandon ship and were in a lifeboat.
“Iran was provided yet another opportunity to demonstrate adherence to the Memorandum of Understanding after being held accountable for earlier attacks on commercial vessels but has again failed,” Centcom wrote on X.
It said US strikes hit 140 Iranian military targets, including missile and drone sites, communication networks, and coastal surveillance locations.
The statement was shared by US Secretary of Defense Pete Hegseth, who wrote: “Iran made a poor choice. Now they pay.”
The IRGC said the US had targeted “a number of coastal bases and telecommunications towers on the southern coast”.
In response, Iran said its “first phase” of retaliation included strikes on the Prince Hassan Air Base in Jordan, saying it had destroyed the base’s command and control centre and MQ9 drone hangars.
On Sunday, US Central Command reiterated the Strait was open, warning the US military was in position to make sure it stayed free-flowing.
Earlier Iran’s parliamentary speaker Mohammad Bagher Ghalibaf, who is also the country’s chief negotiator with the US, wrote on X that the “era of one-sided deals is OVER”.
He went on: “We told you: keep your word or pay the price. Reality is knocking.”
