After weekend talks in Pakistan ended without a deal, Trump threatened to blockade the Strait of Hormuz and also accused Iran of \u201cextortion\u201d. He added that the US Navy would hunt down and interdict ships in international waters that had paid Iran a toll to traverse the strait.<\/p>\n
Later, the US military said it would block all maritime traffic entering and exiting Iranian ports, including those in the Gulf and the Gulf of Oman.<\/p>\n
The US \u200cmilitary\u2019s Central Command (CENTCOM), which has responsibility for operations in the Middle East, told the Reuters news agency that the US \u2060military \u2060will enforce a blockade in the Gulf of Oman and \u2060the Arabian Sea east of the Strait of \u2060Hormuz and it will apply to all vessels regardless of flag.<\/p>\n
\u201cAny vessel entering or departing the blockaded \u2060area without authorisation is subject to \u2060interception, diversion and capture,\u201d it said.<\/p>\n
\u201cThe blockade will not impede neutral transit passage \u200cthrough the Strait of Hormuz to or from non-Iranian \u200cdestinations.\u201d<\/p>\n
Iran\u2019s armed forces, however, said the US \u201cimposition of restrictions on the movement of vessels in international waters is an illegal act and amounts to piracy\u201d.<\/p>\n
Jason Chuah, professor of maritime law at City St George\u2019s, University of London, and the Maritime Institute of Malaysia, told Al Jazeera that Washington\u2019s actions wouldn\u2019t be a classic blockade but a case of \u201csanctions with warships doing the bidding of President Trump\u201d.<\/p>\n
\u201cIt would be much more like a steady pattern of stopping, boarding and seizing vessels thought to be linked to Iran, essentially sanctions enforcement at sea,\u201d he said.<\/p>\n
![\"INTERACTIVE](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2026\/04\/INTERACTIVE-US-naval-blockade-of-Irans-ports-APRIL-13-2026-1776092129.png\")
(Al Jazeera)Is this legal under international maritime law?<\/p>\n
Chuah said the legality of such a blockade by the US is \u201ctricky\u201d.<\/p>\n
\u201cThe United States is not a party to the United Nations Convention on the Law of the Sea, but that does not mean it is free to blockade as it sees fit,\u201d he said. \u201cThe basic rules about freedom of navigation and passage through key waterways are widely accepted as customary international law, so they bind states whether they\u2019ve signed the treaty or not.\u201d<\/p>\n
He added: \u201cNow, if you want to call something a blockade in legal terms, you\u2019re really in the territory of the law of armed conflict at sea \u2013 think the San Remo Manual on International Law Applicable to Armed Conflicts at Sea. That, however, assumes you\u2019re in an actual armed conflict, that you\u2019ve declared the blockade, that it\u2019s effective and that it\u2019s applied even-handedly to neutral ships. That framework sets a high lawfulness bar for blockades.\u201d<\/p>\n
Chuah said that even if Trump uses sanctions as a justification for Washington\u2019s actions regarding Iranian ports, it does not fully resolve the legal issues.<\/p>\n
\u201cEven quite robust domestic sanctions don\u2019t automatically give you the right under international law to stop foreign ships on the high seas without consent or backing from the United Nations Security Council. At best, sanctions may justify why you act but not always where you can act,\u201d he said.<\/p>\n
Will other countries join the US in the blockade?<\/p>\n
So far, only the United Kingdom has clearly stated that it will not join Trump\u2019s blockade of Iranian ports.<\/p>\n
In an interview with BBC 5 Live on Monday, British Prime Minister Keir Starmer said he is focusing on reopening the Strait of Hormuz \u201cas quickly as possible\u201d to reduce global energy prices.<\/p>\n
\u201cWe\u2019re not supporting the blockade, and all of the marshalling diplomatically, politically and capability, \u2026 that\u2019s all focused, from our point of view, on getting the strait fully open,\u201d he said.<\/p>\n
Meanwhile, China has urged calm on all sides.<\/p>\n
Keeping the critical waterway safe, stable and unimpeded serves the common interests of the international community, Ministry of Foreign Affairs spokesperson Guo Jiakun said, adding that China stands ready to work with all sides to safeguard energy security and supplies.<\/p>\n
Featherstone noted that one of the standout features of the US-Israel war on Iran has been how many US allies, such as the UK, have been unwilling to get involved.<\/p>\n
\u201cGiven this blockade would be occurring in the midst of the negotiations over a ceasefire, risking the talks falling apart, it\u2019s unlikely any allies would want to get involved now,\u201d he said.<\/p>\n
\u201cAs with other elements of this war, the [US] administration hasn\u2019t outlined the purpose of this potential blockade. US allies will likely want to know the purpose of the blockade before they commit and risk reprisals,\u201d he added.<\/p>\n
How could a US blockade hurt Iran?<\/p>\n
Even though Iran has become accustomed to US sanctions and has continued to function during the war, a blockade like this could inflict more damage on Iran\u2019s economy.<\/p>\n
The unified command of the Iranian armed forces has said ports in the Gulf and the Sea of Oman are \u201ceither for everyone or for no one\u201d, state broadcaster IRIB reported.<\/p>\n
\u201cThe Armed Forces of the Islamic Republic of Iran consider defending the legal rights of our country a natural and legal duty and, accordingly, exercising the sovereignty of the Islamic Republic of Iran in the territorial waters of our country is the natural right of the Iranian nation,\u201d IRIB quoted Iran\u2019s military as stating.<\/p>\n
\u201cEnemy-affiliated vessels\u201d will not have the right to pass through the Strait of Hormuz while other vessels will be allowed passage, subject to regulations by Tehran, the statement said.<\/p>\n
\u201cThe criminal US\u2019s imposition of restrictions on the movement of vessels in international waters is an illegal act and amounts to piracy.\u201d<\/p>\n
If the security of the ports is threatened, no port in the region \u201cwill be safe\u201d, the statement said.<\/p>\n
Reporting from Doha, Qatar, Al Jazeera\u2019s diplomatic editor James Bays said Washington\u2019s blockade may seek to hit the Iranian economy, which has been doing well despite the war by continuing to get its oil supply through the Strait of Hormuz.<\/p>\n
\u201cIt\u2019s almost a race to the damage on Iran\u2019s economy, a country that\u2019s had sanctions since 1979, that\u2019s very economically resilient although it has deep economic problems,\u201d he said.<\/p>\n
Featherstone said Iran is relatively used to the US having a stranglehold on its economy.<\/p>\n
\u201cIran has experienced enormous US sanctions for decades, and for most of that time, the US sanctions regimes have prevented any nation that trades with the US from trading with Iran,\u201d he said.<\/p>\n
\u201cHowever, after the extent of the US and Israeli strikes on Iran, this would impact their ability to rebuild,\u201d he added.<\/p>\n
What will happen to Iranian mines in the strait?<\/p>\n
On Wednesday, the Islamic Revolutionary Guard Corps (IRGC) released a map of the Strait of Hormuz showing a safe route for ships to follow through the strait, avoiding mines it has laid.<\/p>\n
The map appears to direct ships farther north towards the Iranian coast and away from the traditional route closer to the coast of Oman.<\/p>\n
In a statement, the IRGC said all vessels must use the new map for navigation due to \u201cthe likelihood of the presence of various types of anti-ship mines in the main traffic zone\u201d.<\/p>\n
In his Truth Social post on Sunday about the blockade of the Strait of Hormuz, Trump said US forces will begin clearing the mines that Iran has placed in the strait and added that NATO countries like the UK would help in the process.<\/p>\n
But on Monday, Starmer told BBC 5 Live that while the UK has \u201cminesweeping\u201d capacities, it would not get involved in \u201coperational matters\u201d.<\/p>\n
Meanwhile, Japan said it has yet to decide whether to deploy its Self-Defence Forces for minesweeping operations in the Strait of Hormuz.<\/p>\n
Chief Cabinet Secretary Minoru Kihara told reporters that Japan is urging progress towards a comprehensive understanding between the US and Iran.<\/p>\n
\u201cWhat is most important is that de-escalation, including securing the safety of navigation through the Strait of Hormuz, is actually achieved,\u201d Kihara said, according to the Kyodo News agency.<\/p>\n
![\"Alternative](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2026\/04\/s1-1775729826.jpg\")
\u2018Safe\u2019 routes through the Strait of Hormuz have been announced by Iran\u2019s IRGC, providing new entry and exit pathways for maritime traffic [Screengrab\/Al Jazeera]What does Trump\u2019s blockade mean for shipping in the strait?<\/p>\n
During the US-Israel war on Iran, Tehran has allowed a small number of ships from certain countries it considers \u201cfriendly nations\u201d, such as India, China, Japan, Turkiye and Pakistan, to pass through the strait.<\/p>\n