Iran’s Islamic Revolutionary Guard Corps has announced that the Strait of Hormuz is closed and any transit through the waterway will face “harsh measures”, according to state media.
It added that shipping “to and from ports of allies and supporters of the Israeli-American enemies” is prohibited through any corridor or to any destination.
Three container ships of mixed nationalities were forced to turn back after warnings.
The passage, through which one fifth of the world’s oil and gas passes, has remained largely closed since the outbreak of hostilities.
It comes as Donald Trump is considering sending another 10,000 troops to the Middle East, according to a Wall Street Journal report.
The forces would likely be sent within striking distance of Iran and Kharg Island, a key oil export hub off in the Persian Gulf.
Despite the escalation, Germany’s foreign minister on Friday said the US and Iran have had indirect negotiations and that representatives plan to meet shortly in Pakistan.
Trump said he would again extend the deadline for Iran to reopen the Strait of Hormuz or face the destruction of its energy plants, after Tehran had earlier rejected a 15-point US proposal to end the fighting as unfair.
