The Iranian military command said the Strait of Hormuz has returned to its previous state of 'strict management' due to the US’s continuing blockade of Iranian ports.
The spokesperson said Iran had earlier agreed, 'in good faith', to the managed passage of a limited number of oil tankers and commercial vessels following negotiations, but continued US actions had forced Tehran to restore tighter controls on shipping through the strategic chokepoint.
The war with Iran, which began on February 28 with a US-Israeli attack on the Islamic Republic, has killed thousands, spread to Israeli attacks in Lebanon, and sent oil prices surging because of the de facto closure of the strait.
Despite the initial movement of ships, prospects remained unclear on a resumption of high-level US-Iran talks or any agreement over Iran's nuclear ambitions, a key sticking point.
"It seems to be going very well in the Middle East with Iran," US President Donald Trump told reporters on Air Force One while returning to Washington from Phoenix, Arizona.
"We're negotiating over the weekend. I expect things to go well. Many of these things have been negotiated and agreed to.
"The main thing is that Iran will not have a nuclear weapon. You cannot let Iran have a nuclear weapon, and that supersedes everything else."
He later said the US was having "very good conversations" with Iran, but that Tehran wanted to close the Strait again. Iran could not blackmail the US, he said.
But in sharp contrast, Trump said he might end the ceasefire with Iran unless a long-term deal to end the war was agreed before it expires on Wednesday, adding that a US blockade of Iranian ports would continue.

US peace envoys meet Zelenskyy in Kyiv after Putin talks
US targets three Iranian oil vessels after attack on Navy ships
Israeli strikes kill seven in southern Lebanon
Indonesia's Anak Krakatau eruption halts flights, schools, fishing
Putin says US-Russia contacts beneficial as talks begin with Witkoff and Kushner
Chinese national rescued from Nepal tunnel 10 days after flash flood
US envoys Witkoff, Kushner arrive in Moscow for talks on peace in Ukraine
One dead, 11 people missing after mudslide in China's Jiangxi province
