US President Donald Trump said on Monday that the American military has begun a blockade of Iranian ports to pressure Iran to reopen the Strait of Hormuz and agree to end the ongoing conflict.
Trump said the move was aimed at stopping what he described as Iran’s attempts to “blackmail” global trade.
The blockade targets vessels entering or leaving Iranian ports along the Persian Gulf and Gulf of Oman, according to the United States Central Command.
Iran responded with warnings that no port in the region would remain safe, escalating fears of a wider confrontation that could disrupt global energy supplies and end the fragile ceasefire.
A notice from the UK Maritime Trade Operations agency said the blockade applies to the entire Iranian coastline, though ships travelling between non-Iranian destinations may still pass through the strait with caution due to increased military presence.
Shipping data indicated immediate disruption, with at least two tankers turning back after the blockade began. Traffic through the strait had already fallen sharply since the conflict started on February 28, from over 100 vessels a day to a fraction of that number.
The Strait handles about 20 percent of global oil trade, and the disruption has pushed oil prices close to $100 per barrel, up from about $70 before the war.
Iranian officials dismissed the blockade as ineffective. Parliament speaker Mohammad Bagher Ghalibaf warned that Iran would respond if confronted, while other officials said the move would further destabilise markets.
The conflict has caused thousands of casualties across the region, including Iran, Israel, and neighbouring countries, and killed US service members.
Meanwhile, US officials are considering another round of talks with Iran before the ceasefire deadline of April 22. Discussions are ongoing, with potential venues including Geneva and Islamabad, as diplomats explore the possibility of extending the truce to allow more time for negotiations.
Vice President JD Vance said earlier talks stalled over disagreements on Iran’s nuclear programme, while Iran maintains its programme is peaceful.
Despite the escalation, US officials said communication channels remain open, with continued efforts to reach a diplomatic resolution.