US threatens to strike Iran's Kharg Island oil network after military targets 'obliterated'

US President Donald Trump threatened to strike the oil infrastructure of Iran's Kharg Island hub unless Tehran stopped attacking vessels in the Strait of Hormuz, a warning that could further roil markets coping with a historic supply disruption.

Trump paired his ultimatum with a social media post saying the United States had "totally obliterated" military targets on the island, the export terminal for 90 per cent of Iran's oil shipments, which lies about 500km northwest of the strait.

U.S. strikes did not target Kharg's oil infrastructure, but "should Iran, or anyone else, do anything to interfere with the Free and Safe Passage of Ships through the Strait of Hormuz, I will immediately reconsider this decision," Trump wrote.

Iran could not defend against US attacks, the president said. "Iran’s Military, and all others involved with this Terrorist Regime, would be wise to lay down their arms, and save what’s left of their country, which isn’t much!" he posted on his Truth Social platform.

He later posted: "The Fake News Media hates to report how well the United States Military has done against Iran, which is totally defeated and wants a deal - But not a deal that I would accept!"

Iran, however, showed no sign of capitulating or bowing to US-Israeli military pressure.

Iran's armed forces responded to the Kharg attack by saying any strike on their country's oil and energy infrastructure would lead to strikes on facilities owned by oil companies cooperating with the United States in the region, Iranian media reported.

Iran's semi-official Fars news agency reported, citing sources, that more than 15 explosions were heard on the island during the US attacks. The sources said air defences, a naval base and airport facilities were hit, but there was no damage to oil infrastructure.

Markets were watching for any sign that US strikes had damaged the island's intricate network of pipelines, terminals and storage tanks. Even minor disruptions could further tighten global supply, adding pressure to a volatile market.

Oil prices have swung sharply on Trump's changing comments about the likely duration of the war, which began on February 28 with massive US and Israeli bombardments of Iran and quickly spread into a regional conflict with broad consequences for worldwide energy and stock markets.