President Donald Trump issued a stark 48-hour ultimatum to Iran on Saturday evening via Truth Social, demanding the full reopening of the Strait of Hormuz without threats or face devastating strikes on its power infrastructure.

"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!" Trump posted from his Florida residence.

The demand comes amid the fourth week of open war between the United States, Israel, and Iran, which erupted on February 28 after U.S. and Israeli strikes targeted Iranian military and nuclear sites, including the killing of Supreme Leader Ayatollah Ali Khamenei. Iran has retaliated with missile and drone attacks on Israel, Gulf states hosting U.S. forces, and bases like the joint U.S.-U.K. Diego Garcia facility in the Indian Ocean.

Late Saturday, Iranian missiles struck communities near Israel's Dimona nuclear research center in Arad and Dimona, injuring dozens and damaging buildings in the first such penetration of Israeli defenses in the area, according to reports. The International Atomic Energy Agency reported no damage or radiation leaks at Iran's Natanz nuclear site following an earlier strike, which Israel denied carrying out.

The Strait of Hormuz, through which about 20% of global oil and liquefied natural gas flows, has seen commercial shipping grind to a halt due to Iranian threats, attacks on vessels, and skyrocketing insurance costs, even without a formal blockade. Brent crude prices have surged from around $72 per barrel before the war to over $106 on Saturday, fueling global economic concerns.

The U.S. has conducted strikes on suspected Iranian minelaying vessels and coastal missile sites, degrading Tehran's anti-shipping capabilities, while deploying additional warships and 2,500 Marines to the region, bringing total U.S. personnel to about 50,000. The Pentagon requested $200 billion from Congress to sustain operations. To ease oil pressures, the administration temporarily lifted sanctions on Iranian oil already at sea, releasing 140 million barrels, tapped the Strategic Petroleum Reserve, and eased some Russian oil restrictions, though effects have been limited.

Trump has urged allies, including NATO members, to help secure the strait post-conflict, calling some "cowards" for hesitation, while stating the U.S. could handle it alone if needed and anticipates winding down major operations once threats are neutralized. Casualties in the conflict exceed 1,500 in Iran, 15 in Israel from missiles, at least 13 U.S. service members, and dozens of civilians in Gulf states.

No immediate response from Iran to the ultimatum has been reported, as clashes continue, including Israeli operations against Hezbollah in Lebanon.