Tehran: Iran’s Islamic Revolutionary Guard Corps (IRGC) on Sunday issued a sharp warning to the United States, saying any miscalculation in the Strait of Hormuz would trap adversaries in a “deadly vortex,” in response to US President Donald Trump announcing a naval blockade of the key shipping route.

The IRGC’s naval command said Iranian forces have full control over the strategic waterway, a vital artery for global oil shipments. “All traffic... is under the full control of the armed forces,” the Guards said in a post on X.

“The enemy will become trapped in a deadly vortex in the Strait if it makes the wrong move,” it added, sharing visuals of vessels being tracked in targeting systems.

The warning comes hours after Trump declared that the US Navy would “immediately” begin blockading ships entering or leaving the Strait of Hormuz, escalating tensions following the collapse of US-Iran nuclear talks.

Trump had said the US was “LOCKED AND LOADED” and prepared to act militarily, signalling a significant hardening of Washington’s stance after negotiations failed to yield an agreement.

The breakdown in talks, held over 21 hours in Pakistan, has left a fragile two-week ceasefire in doubt, with both sides blaming each other for the deadlock. US officials said Iran refused to commit to abandoning its nuclear weapons ambitions, while Tehran accused Washington of overreach.

The Strait of Hormuz, located between Iran and Oman, handles nearly a fifth of the world’s oil supply, making any escalation in the region a major concern for global energy markets.

The top Iranian official in the Islamabad talks, parliamentary speaker Mohammad Bagher Ghalibaf, said on X that Washington was "unable to gain the trust of the Iranian delegation in this round of negotiations".

Iranian and US media said the main sticking points in the talks were the Strait of Hormuz and Tehran's insistence on the right to enrich uranium.

Trump threatens China

Trump threatened 50 per cent tariffs on Chinese goods imported into the United States if Beijing helps Iran militarily.

"If we catch them doing that, they get a 50 per cent tariff, which is a staggering -- that's a staggering amount," Trump told Fox News.