US Central Command said the measure took effect at 10 a.m. ET (15:00 BST) on 13 April and applies to all vessels entering or leaving Iranian ports on the Gulf and the Gulf of Oman. It added that ships transiting the Strait of Hormuz to and from non-Iranian ports would not be obstructed.
Iran’s Islamic Revolutionary Guard Corps responded by saying any military vessel approaching the strait would be regarded as violating the ceasefire and would be dealt with severely.
The move followed the collapse of US-Iran talks over the weekend. Reuters reported that the failed negotiations triggered Washington’s decision to go ahead with the blockade.
Shipping markets reacted quickly. Reuters reported that oil tankers were already steering clear of the Strait of Hormuz ahead of the blockade, with some vessels turning away from the Gulf while others exited before the measure took effect.
Oil prices also jumped on Monday. AP reported that US crude rose to $103.69 a barrel and Brent to $102.24, while Reuters said crude rose by more than 7% as traders reacted to the latest developments around Hormuz.
Reuters also reported that the blockade could keep around 2 million barrels a day of Iranian oil off the market.
