Iran vowed on Wednesday not to reopen the Strait of Hormuz so long as a US naval blockade remained in place despite a ceasefire extension, as it announced the seizure of two ships trying to cross the strategic waterway.
As the clock ticked for a return to the war that has engulfed the region, US President Donald Trump had said on Tuesday he would maintain the truce to allow more time for Pakistani-brokered peace talks .
Iran said it welcomed the efforts by Pakistan but made no other comment on Trump's announcement.
"A complete ceasefire only has meaning if it is not violated through a naval blockade," said Iranian parliament speaker Mohammad Bagher Ghalibaf, who led Tehran's delegation in the first round of talks in Islamabad.
"Reopening the Strait of Hormuz is not possible amid a blatant violation of the ceasefire." Oil prices , which have soared since Israel and the United States attacked Iran on February 28, kept inching up from the uncertainty on whether war will resume, although US stock prices gained ground.
Trump had said he wanted to give time for Iran's "fractured" leadership to come up with a proposal, in what many observers saw as a face-saving way to avoid renewed war.
Trump told the New York Post that talks could resume in Pakistan within two to three days, even though Iran has not confirmed participation and Vice President JD Vance put on hold his travel to Islamabad on Tuesday.
Trump also claimed that Iran at his request had halted alleged plans to execute eight women arrested over massive anti-government protests in the weeks before the attack.
But Iran's judiciary described his remarks as "false news", saying the women had never faced the death penalty. Ships seized Iran's elite Revolutionary Guards said they forced two ships to the Iranian shore from the Strait of Hormuz, the narrow gateway for one-fifth of the world's oil.
"The Islamic Revolutionary Guard Corps naval force this morning identified and stopped in the Strait of Hormuz two violating ships," the Guards said in a statement.
They identified the vessels as the Panama-flagged container ship MSC Francesca and the Liberia-flagged Epaminondas.
Panama's foreign ministry confirmed the seizure of the MSC Francesca, calling it a "serious attack on maritime security" and an "unnecessary escalation".
UK-based maritime security monitors confirmed that three commercial vessels had reported incidents involving gunboats in the strait.
Among them, a container ship reported being fired upon by a Revolutionary Guards boat 15 nautical miles northeast of Oman, causing damage to the bridge but no casualties, monitor UKMTO said.
Under orders from Trump, the US Navy is attempting to block vessels heading to or from Iranian ports, seeking to ramp up pressure on the Iranian economy even without all-out war.
In the midst of the blockade, the Pentagon announced on Wednesday that the Secretary of the Navy John Phelan would leave "immediately."
It gave no reason for his sudden departure, the latest removal of a senior officer under Trump's combative Pentagon chief, Pete Hegseth.
Iran in retaliation for being attacked has said that vessels must seek permission to leave or enter the Gulf through the strait. It had earlier promised free passage during the ceasefire but returned to defiance after Trump announced the blockade.
The US Defense Department said on Tuesday that US forces had intercepted and boarded a "stateless sanctioned" vessel. AFP has identified the ship as one linked to Iranian activity. Both sides accuse the other of ceasefire breaches.