Iranian leader Ayatollah Ali Khamenei has threatened to sink US ships as tensions boil in the Middle East. In a fiery warning posted online, he said Tehran possessed weapons capable of sending American vessels “to the bottom of the sea”.

The remarks came as Washington moved naval forces toward the Persian Gulf, a move Iranian officials have portrayed as intimidation. Posting on X, the Iranian cleric warned US forces they would not be safe operating near the country’s coastline. His comments add to fears of a potential flashpoint in the Strait of Hormuz, one of the world’s most vital oil shipping routes. Issuing a warning over US naval deployments, he said: “The Americans constantly say that they’ve sent a warship toward Iran. Of course, a warship is a dangerous piece of military hardware. However, more dangerous than that warship is the weapon that can send that warship to the bottom of the sea.”

He appeared to be referring to Iran’s anti-ship capabilities, although he did not name a specific system.

According to US defence assessments and analysis by the Center for Strategic and International Studies, Tehran has invested heavily in coastal missiles, naval mines and fast-attack craft designed to threaten ships operating close to its shores.

Washington has recently deployed major naval forces to the region, including the aircraft carriers USS Abraham Lincoln (CVN-72) and USS Gerald R. Ford (CVN-78).

Both vessels are nuclear-powered carriers capable of launching sustained air operations far from US territory.

The threats come as the United States and Iran begin a new round of indirect nuclear negotiations in Geneva aimed at resolving disputes over Tehran’s nuclear programme.

Speaking aboard Air Force One, Donald Trump said he believed Iran wanted a deal but warned there would be consequences if talks failed.

He said Tehran had previously experienced those consequences, referring to US strikes on Iranian nuclear facilities last year.

Iran has responded with its own show of force, launching naval drills in the Strait of Hormuz.

Officials on both sides say negotiations are ongoing, despite rising tensions and exchanges of threats.