The United States Navy has commenced a blockade of the Strait of Hormuz following the collapse of ceasefire negotiations between the United States and Iran in Islamabad. The blockade, announced by President Donald Trump, is set to restrict ships entering or leaving Iranian ports, with enforcement beginning at 10 am Eastern Time on 13 April 2026. The US Central Command stated that the measure will be applied impartially to vessels of all nations, but ships traveling between non-Iranian ports will still be permitted to transit the strait. The move comes amid heightened tensions and ongoing conflict in the region.According to Hindustan Times, the US Navy’s blockade follows 21 hours of direct negotiations in Islamabad that ended without agreement. The US official position is that the blockade aims to demonstrate the limits of Iran’s leverage and to prevent Iran from profiting through oil sales during the conflict. The US Central Command clarified that the blockade would be enforced against all vessels entering or departing Iranian ports, while non-Iranian shipping would not be impeded.As highlighted by Financial Express, President Donald Trump stated that any Iranian-linked ships in the Strait of Hormuz would be blocked, and warned that any Iranian attack on US forces or ships would result in overwhelming retaliation. Iran’s Islamic Revolutionary Guard Corps responded by asserting full control over the strait and warning that any military vessels entering the area would be treated as ceasefire violations and met with a severe response. The fragile ceasefire, in place since 7 April, has been further destabilised by these developments.As noted in an article by The Guardian, the announcement of the blockade has caused oil prices to surge above $100 per barrel, with Brent crude rising nearly 7% and US crude climbing over 8%. The economic impact is being felt globally, with Asian stock markets experiencing declines and analysts warning that the risk associated with the Strait of Hormuz is structural and significant for the global economy. The United Nations Development Programme has estimated that more than 32 million people worldwide could be pushed into poverty due to the economic fallout from the ongoing conflict.“Effective immediately, the United States Navy, the Finest in the World, will begin the process of BLOCKADING any and all Ships trying to enter, or leave, the Strait of Hormuz,” President Donald Trump stated in his official announcement.As coverage revealed, the blockade is expected to have cascading effects beyond Iran, particularly impacting China, which is a major importer of Iranian oil. The US has indicated that freedom of navigation will not be impeded for vessels transiting to and from non-Iranian ports. However, the right of “visit and search” will be exercised, allowing US forces to inspect vessels and determine their eligibility to proceed. Experts have noted that this could inflict significant economic damage on Iran by denying it oil export revenue, while also creating challenges for countries reliant on Iranian oil.Iran has threatened to respond by targeting other global chokepoints, such as the Bab al-Mandeb Strait, which connects the Red Sea to the Gulf of Aden. In the event of further escalation, reporting indicated that Iran could deploy regional allies, including the Houthis in Yemen, to disrupt global energy flows and trade. Maritime advisories have warned of potential hostile actions, including drone and missile attacks, in the region.US Vice President JD Vance reiterated that Washington’s core objective remains preventing Iran from acquiring nuclear weapons. The blockade is part of a broader strategy to pressure Iran economically and diplomatically. Analysis showed that the surge in oil prices has led to increased volatility in global energy markets, with energy sector stocks experiencing heightened activity and uncertainty regarding future supply.“Iran will never have a nuclear weapon!” President Donald Trump reiterated, while Iran’s Revolutionary Guard Corps maintained that “all traffic is under the full control of the armed forces.”During the blockade’s initial hours, shipping activity in the Strait of Hormuz was significantly disrupted, with some vessels turning back and overall traffic dropping sharply. Further details confirmed that the US Navy has deployed assets such as the USS Tripoli, capable of rapid response and equipped with advanced military capabilities. The situation remains fluid, with both sides issuing warnings and the international community closely monitoring developments.Diplomatic efforts to resolve the crisis have so far failed, and the blockade’s enforcement is expected to continue as long as the core issues between the United States and Iran remain unresolved. The broader implications for global trade, energy security, and regional stability are still unfolding as details emerged.Note: This article is produced using AI-assisted tools and is based on publicly available information. It has been reviewed by The Quint's editorial team before publishing.