Trump's threat to target power plants carries more risks. A regional "blackout," as Iranian officials warned, would cripple hospitals, water desalination plants and food distribution across the Gulf.

TEHRAN, March 23 (Xinhua) -- A sharp escalation in the Iran-U.S.-Israel conflict is unfolding as U.S. President Donald Trump on Saturday issued a 48-hour ultimatum demanding Iran fully reopen the Strait of Hormuz, warning of sweeping strikes on the country's power infrastructure, while Tehran signaled it would retaliate across the region if attacked.

The ultimatum comes after Iranian forces strictly controlled access to the Strait of Hormuz, in response to U.S. and Israeli airstrikes on its military and nuclear sites.

"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 wrote in a post on Truth Social.

KEY FLASHPOINT

Iranian forces warned of broader retaliation if the U.S. targets its power facilities. Iranian Parliament Speaker Mohammad Bagher Ghalibaf on Sunday said that energy and oil infrastructure across the region could face "irreversible" destruction if the United States targets Iran's power plants.

Any attacks would make "vital infrastructure and energy and oil facilities throughout the region ... legitimate targets" and cause oil prices to rise for an extended period, Ghalibaf said on X.

Earlier Sunday, Iran's primary military command, Khatam al-Anbiya Central Headquarters, issued a similar warning, saying it would strike U.S. and Israeli "energy, information technology and desalination infrastructure" in the region if its energy infrastructure was attacked, according to Fars News Agency.

Iranian military authorities said the Strait of Hormuz could be fully closed if attacks materialize, though the Foreign Ministry maintained that the waterway remains open under wartime monitoring.

The Strait of Hormuz, a vital global energy corridor bordered by Iran to the north, through which around a fifth of global oil and liquefied natural gas supply passes, has become a key flashpoint in the war.

ATTACKS ON ENERGY FACILITIES

On Feb. 28, Israel and the United States launched joint attacks on Tehran and several other Iranian cities, killing Iran's then Supreme Leader Ali Khamenei, along with senior military commanders and civilians. Iran responded by launching waves of missile and drone strikes targeting Israel and U.S. bases and assets in the Middle East and strictly controlling access to the Strait of Hormuz.

In recent days, near-daily strikes have targeted Iranian military installations, missile production sites and command centers. Iran said the United States and Israel carried out a major airstrike Saturday on Natanz, its primary uranium enrichment facility. Neither government has officially claimed responsibility, while Israeli media suggest the U.S. bombers carried out the strike.

The International Atomic Energy Agency said no radiation leak was detected, but confirmed damage to underground halls and centrifuges.

Iran retaliated by launching ballistic missiles at southern Israeli cities near the country's Negev nuclear research center. The strikes injured almost 200, according to Israeli officials.

BROADER IMPACT

Beyond immediate military exchanges, the conflict is raising alarm over potential strikes on energy and civilian infrastructure, which analysts warn could have far-reaching humanitarian and environmental consequences.

Trump's threat to target power plants carries more risks. A regional "blackout," as Iranian officials warned, would cripple hospitals, water desalination plants and food distribution across the Gulf.

Desalination facilities in Saudi Arabia, the UAE and other states supply 70% or more of drinking water, as attacks there could trigger humanitarian disasters affecting tens of millions. Oil infrastructure strikes would trigger massive spills, environmental damage to the Gulf ecosystem and further price spikes.

NARROW WINDOW FOR DIPLOMACY

Trump's ultimatum against Iran signaled an escalation one day after he said Washington was considering "winding down" military efforts in the region.

However, Trump administration advisers, including envoys Steve Witkoff and Jared Kushner, have begun preliminary internal discussions on potential post-conflict frameworks, Axios reported, citing U.S. officials.

No formal channels have reopened so far, and Iranian leaders insist that talks can only happen after the strikes end.

The 48-hour clock is ticking amid one of the most dangerous moments in the four-week conflict. The coming days will determine whether the crisis spirals into a wider regional war or opens a path back to negotiations.