U.S. President Donald Trump has issued a stark and dramatic warning amid escalating tensions with Iran, declaring that “a whole civilization will die tonight” if the crisis is not resolved.

In a message posted on his Truth Social platform ahead of a critical deadline, Trump suggested that developments within hours could mark a decisive turning point in global affairs. While expressing reluctance over such an outcome, he indicated that the situation could spiral beyond control, adding that he did not want it to happen “but it probably will.”

Trump also alluded to the possibility of sweeping political transformation in Iran, referencing what he described as “complete and total regime change,” which he claimed could produce “revolutionarily wonderful” outcomes.

The warning comes as Washington intensifies pressure on Tehran to reopen the Strait of Hormuz, a critical maritime corridor through which a significant portion of the world’s oil supply is transported. The closure or disruption of the passage has heightened concerns over global energy security and economic stability.

According to reports, the U.S. administration has issued a deadline of 20:00 EDT (midnight GMT) on Tuesday for compliance, raising fears of imminent military or economic escalation should the ultimatum expire without resolution.

Framing the standoff in sweeping historical terms, Trump accused Iran’s leadership of decades of “extortion, corruption, and death,” asserting that the unfolding situation represents a defining moment in global history.

“We will find out tonight, one of the most important moments in the long and complex history of the world,” he stated, concluding his remarks with a message of goodwill directed at “the great people of Iran.”

The rhetoric reflects mounting international concern over stability in the Gulf region, particularly given the strategic importance of the Strait of Hormuz. Any sustained disruption to the waterway could trigger sharp increases in global oil prices and wider geopolitical consequences.

The latest developments mark a significant escalation in already strained relations between Washington and Tehran. Tensions have persisted for years over Iran’s nuclear programme, regional influence, and repeated confrontations in the Gulf, including incidents involving oil tankers and military patrols in the strategic corridor.