US President Donald Trump has declared that American naval forces will begin blocking vessels attempting to pass through the Strait of Hormuz, dramatically intensifying tensions with Iran after high-level negotiations failed to yield an agreement.

In a statement, Trump said the US Navy would immediately start enforcing measures against ships entering or exiting the strategic waterway. He accused Tehran of failing to uphold assurances about keeping the passage open and alleged that fears over possible naval mines had already disrupted maritime traffic.

The Strait of Hormuz is a crucial global energy corridor, responsible for transporting roughly one-fifth of the world’s oil supply. Any interference in its operations carries significant consequences for international energy markets.

Nuclear Issue Remains Core Dispute

Trump revealed that nearly 20 hours of discussions with Iranian representatives in Islamabad led to progress on several fronts, but ultimately broke down over Tehran’s nuclear programme. According to him, Washington’s primary demand — a firm guarantee that Iran would not pursue nuclear weapons — was not met.

He reiterated that preventing Iran from acquiring nuclear arms remains the central objective of US policy, stressing that other areas of discussion were secondary. The President added that he had been briefed on the talks by Vice President JD Vance and senior officials involved in the negotiations.

Praise for Pakistan’s Mediation

Trump commended Pakistan’s leadership for hosting and facilitating the dialogue, describing both Prime Minister Shehbaz Sharif and Field Marshal Asim Munir as capable partners in attempting to de-escalate tensions. He suggested that their involvement had helped prevent a wider regional conflict.

Escalation in the Gulf

By ordering a blockade, Washington is effectively asserting control over one of the most sensitive maritime routes in the world. Trump framed the action as a response to what he characterised as Iranian attempts to pressure shipping companies through threats and uncertainty.

He warned that vessels suspected of cooperating with Tehran’s demands would face interception, and stated that any hostile action against US forces or commercial ships would draw a forceful response. Trump also claimed that Iran’s military infrastructure had been significantly weakened in recent confrontations.

Iran Blames US for Breakdown

The blockade announcement follows the collapse of a two-week ceasefire designed to create space for diplomacy. Iranian officials, including Parliamentary Speaker Mohammad Baqer Qalibaf, said the talks failed because Washington did not take sufficient steps to build mutual confidence.

Iranian representatives maintained that while some common ground was identified, core disagreements — particularly surrounding nuclear policy and maritime security — remained unresolved. US Vice President JD Vance said Tehran declined to accept American conditions, including long-term assurances on nuclear development.

With no agreement in place and tensions rising around a vital global trade artery, the situation now poses significant risks not only for the region but also for the global economy.