The status of a two-week-old ceasefire remained unclear. In a sharp about-face hours after threatening renewed violence, Trump made what appeared to be a unilateral announcement on Tuesday that the Unied States would extend a ceasefire until it had discussed an Iranian proposal in peace talks to end the two-month-old war.
But Iranian officials did not say they had agreed to any extension of the truce, and criticised Trump's decision to maintain the US Navy blockade of Iran's trade by sea, itself considered by Iran an act of war.
Iran's parliament speaker and lead negotiator Mohammad Baqer Qalibaf said a full ceasefire only made sense if the blockade was lifted. Reopening the Strait of Hormuz, the slender chokepoint that carried one-fifth of the world's oil trade before the war, was impossible with such a "flagrant breach of the ceasefire," Qalibaf said on social media.
"You did not achieve your goals through military aggression and you will not achieve them by bullying either," he wrote in his first response to Trump's announcement.
"The only way is recognising the Iranian people's rights."
Trump again backed away at the last moment from his repeated threats to bomb Iran's power plants and other civilian infrastructure, which the United Nations and others warn would violate international humanitarian law. But little progress has been made in ending the war that started with joint US-Israeli attacks on Iran on February 28.
That leaves the two sides in a holding pattern with the crucial Strait of Hormuz still effectively shut, straining economies across the world.
Thousands of people have been killed across the Middle East, mostly in Iran and Lebanon, where the Iran-allied Hezbollah militant group joined the fighting against Israel.
The Islamic Revolutionary Guards Corps seized two vessels for what it called maritime violations and escorted them to Iranian shores, according to statements by the shipping companies and Iran's semi-official Tasnim news agency. It was the first time Iran has seized ships since the war began at the end of February.
In his Tuesday announcement, Trump said the US had agreed to a request by Pakistani mediators "to hold our Attack on the Country of Iran until such time as their leaders and representatives can come up with a unified proposal ... and discussions are concluded, one way or the other."
Pakistan, which has acted as a mediator, was still trying to bring the sides together after both failed to show up for tentatively scheduled talks in Islamabad on Tuesday before the two-week-old ceasefire was due to expire.
Both Iran and the US-Israel alliance have continued to claim to be winning the war. Iran showcased some of its ballistic weapons at a parade in Tehran on Tuesday evening, with images on state TV showing large crowds waving Iranian flags and a banner in the background with a fist choking off the strait.
Before the war, around 130 vessels crossed the strait each day, a figure that has plummeted to just a handful a day since fighting began.
The US military on Wednesday said it had so far directed 29 vessels to turn around or return to port as part of the US blockade against Iran. Far beyond the Gulf, the US military has also intercepted at least three Iranian-flagged tankers in Asian waters, sources said, redirecting them away from their positions near India, Malaysia and Sri Lanka.
A first session of peace talks between Iran and the US in Islamabad 11 days ago produced no agreement.
