Iran's Islamic Revolutionary Guard Corps (IRGC) said on Tuesday it has widened its definition of the strait of Hormuz into a "vast operational area", extending it from the coast of Jask to Siri Island.
The move broadens the area the IRGC says falls under its Hormuz operations beyond the narrow strait itself, through which around a fifth of global oil supply transited before the US-Iran war began.
In a statement carried by Iranian state media, Mohammad Akbarzadeh, deputy political director of the IRGC Navy, said the strait of Hormuz had previously been "defined as a limited area around the Hormuz and Hengam islands", but that definition has now changed. "Within our new framework, the area of the strait of Hormuz has been significantly expanded, and today it extends beyond the large islands, from the coast of Jask to Siri Island."
Iran's Siri Island lies in the Mideast Gulf around 70km west of the UAE emirate of Umm al-Quwain. The port of Jask is on Iran's southern coast, east of the strait of Hormuz. Akbarzadeh said the area had expanded from 20-30 miles previously to more than 200-300 miles. He described the new footprint as "a complete crescent".
This is the second expansion the IRGC has announced since war with the US and Israel prompted Iran to effectively close the strait.
On 4 May, the IRGC published two maps showing an expanded area it said was "under its management and control". The outlined area extended from the western tip of Iran's Qeshm Island in the Mideast Gulf to Umm al-Quwain west of the strait, and to Kuh Mobarak in southern Iran and the UAE emirate of Fujairah east of the strait.
The area outlined on Tuesday by the IRGC Navy extends beyond the borders shown in the 4 May maps.
The new definition comes as tensions between Iran and the US grow over the continued disruption of shipping. US president Donald Trump has repeatedly claimed agreements with Iran that he said should restore at least some traffic through the strait. But little has changed since the war began, prompting the US to impose a blockade of its own on vessels travelling to and from Iranian ports last month.
Washington and Tehran have been exchanging proposals in recent weeks aimed at ending the conflict, but prospects for a breakthrough appear remote. Trump on Monday described Iran's latest offer as a "piece of garbage" and warned that the ceasefire, in place since 8 April, is under strain.
