Tehran will retaliate against any company unloading Iranian oil from a seized tanker, the Islamic Revolutionary Guards Corps' navy commander Alireza Tangsiri told state media on Thursday.
In April, the US confiscated Iranian oil on a boat off the coast of Malaysia in an operation purported to enforce sanctions.
Mr Tangsiri said Tehran was holding Washington responsible for the unloading of the tanker's cargo.
Sources familiar with the matter told Reuters on anonymity that Washington had taken control of the oil on board the Suez Rajan after being granted a court order.
On Monday, the US announced it would send additional F-35 and F-16 fighter jets, along with a warship, to the Middle East, in a bid to monitor key waterways in the region after Iran's seizure and harassment of commercial ships in recent months.
Since 2019, a series of attacks on ships in Gulf waters have taken place, increasing tension between the US and Iran.
About a fifth of the world's crude and oil products passes through the Strait of Hormuz between Iran and Oman.
There has been a spate of military seizures and attacks on commercial vessels in Gulf waterways this year, including the seizure of two tankers in the space of a week in May, one of them bound for Texas.
The US Navy said the latest deployment of a warship was intended “to help ensure regional maritime security and stability”.
In April, the IRGC released footage of its forces seizing the US-bound, Chinese-owned Advantage Sweet tanker, showing commandos boarding its decks, descending on ropes from a helicopter.
“Iran’s continued harassment of vessels and interference with navigational rights in regional waters are a threat to maritime security and the global economy,” the US Navy's Bahrain-based Fifth Fleet said at the time.
Since then, Iran has fired on a tanker, causing light damage to the Richmond Voyager off the coast of Oman. The US Navy released drone footage of the incident on July 5, saying the USS McFaul missile destroyer stopped the vessel from being seized.
