President Donald Trump threatened that “a whole civilization will die tonight” if his deadline given to Iran to reopen the Strait of Hormuz is ignored.

“A whole civilization will die tonight, never to be brought back again. I don’t want that to happen, but it probably will,” he posted Tuesday on Truth Social in one of his gravest threats yet.

Trump earlier threatened to annihilate Iran’s bridges, power plants and other civilian infrastructure ― attacks that would amount to war crimes under international law ― unless a deal is struck by 8 p.m. Eastern time Tuesday.

He stressed in his post that there’s still time for a deal to be reached, in what would amount to “one of the most important moments in the long and complex history of the World.”

“47 years of extortion, corruption, and death, will finally end,” he wrote, referencing the anniversary of the 1979 Islamic Revolution. “God Bless the Great People of Iran!”

Despite the increase in disturbing and violent threats made by Trump against Iran, there have been no reports that a deal is close to being reached.

After Trump on Sunday posted an expletive-laden threat about obliterating the country’s infrastructure, Iran rejected a 45-day ceasefire proposal, saying it instead wants a permanent end to the war.

Iranian officials on Tuesday urged young people to form human chains around the country’s power plants ahead of Trump’s deadline.

Vice President JD Vance, at a press conference in Hungary on Tuesday, said the U.S. is “confident” Iran will respond by Trump’s deadline and noted if it’s not “the right response,” the U.S. is prepared to take further action.

“We’ve got tools in our tool kit that we so far haven’t decided to use. The president of the United States can decide to use them and will decide to use them if the Iranians don’t change their course of conduct,” he said.