Donald Trump has warned Iran the United States will “obliterate” Iran’s power plants unless the Strait of Hormuz is re-opened within 48 hours.

The US president issued the ultimatum in an angry post on Truth Social.

Around one-fifth of the world’s oil supply passes through the Strait of Hormuz, but Iran has been attacking tankers trying to use it since the war began three weeks ago.

That has led to a spike in the price of oil, triggering a potential global economic crisis as energy costs soar.

Trump said: “If Iran doesn’t FULLY OPEN, WITHOUT THREAT, the Strait of Hormuz, within 48 HOURS from this exact point in time, the United States of America will hit and obliterate their various POWER PLANTS, STARTING WITH THE BIGGEST ONE FIRST!”

It came just a day after Trump said America was preparing to “wind down” its operations in Iran.

In another Truth Social post on Friday, he said: “We are getting very close to meeting our objectives as we consider winding down our great Military efforts in the Middle East with respect to the Terrorist Regime of Iran.”

He said the Strait of Hormuz “will have to be guarded and policed”, but said that responsibility would fall on other countries which rely on it for their oil supply.