Iran vowed on Thursday to make the United States regret attacking the Islamic republic and said it would keep up a chokehold on the Strait of Hormuz that has sent oil prices soaring.

The International Energy Agency warned that the Middle East war could lead to "the largest supply disruption" in oil industry history, but US President Donald Trump wrote on social media that defeating Iran's "evil empire" was more important than crude prices.

Trump has faced intense political pressure as the global economic fallout of the crisis has mounted, and he has given mixed messages as to when the US campaign might end.

"While starting a war is easy, it cannot be won with a few tweets. We will not relent until making you sorry for this grave miscalculation," Iranian security chief Ali Larijani said on X.

His comments came after Iran's new supreme leader, Mojtaba Khamenei, issued a defiant statement – his first since being appointed on Sunday after the death of his father and predecessor Ali Khamenei in a strike.

Mojtaba Khamenei, who was reportedly wounded, has yet to appear publicly since his nomination, and his message calling for vengeance was read by an anchor on state television.

"The lever of blocking the Strait of Hormuz must definitely be used," Khamenei said of the waterway through which a fourth of the world's seaborne oil trade usually transits.

The strait normally accounts for a fifth of the world's liquefied natural gas (LNG) supplies.

In an interview with AFP, Iran's deputy foreign minister Majid Takht-Ravanchi said Tehran was acting only in "self defence" and wanted to ensure that war could not be "imposed" on it again.

Takht-Ravanchi confirmed that Iran had been approached by some "friendly countries" to put an end to the conflict, without specifying which ones.

"We are telling them the same thing, that we want the ceasefire to be part of an overall formula for ending the war altogether," he said.

Gulf states have borne the brunt of retaliatory attacks from Iran, which said on Thursday that it would "set the region's oil and gas on fire" if its own energy infrastructure and ports were attacked.

Images from Bahrain on Thursday showed thick smoke rising after a strike on fuel tanks in Muharraq, with residents told to stay inside and close their windows. Drones caused damage again at Kuwait's international airport and in downtown Dubai, while Saudi Arabia said it had intercepted drones headed towards its Shaybah oil field and its embassy district.

With Gulf states slashing production and oil tankers stuck in the Gulf, benchmark oil prices have risen 40 to 50 percent since the US and Israel attacked Iran on February 28, threatening to crimp growth and stoke inflation.

In Iraq, six French soldiers were wounded by a drone attack in the autonomous Kurdistan region in the country's north, the French military said on Thursday.

And a US KC-135 refueling aircraft crashed in western Iraq, at least the fourth American military aircraft to be lost in the conflict, after three F-15 jets were downed by friendly fire. (AFP)



Edited by Cecil Wong