Iran has cut off direct communications with the US as women and children formed human shields around energy sites after Donald Trump warned that a 'whole civilization will die tonight.'

Negotiations are continuing through mediators but the severed contact has complicated efforts to meet Trump's 8pm ET deadline, the Wall Street Journal reported. 

An official said that Iran intended to convey a message of defiance and disapproval by severing communications.

Iranian state TV is now broadcasting images of civilians protesting at bridges and power plants, in a direct taunt after Trump threatened to strike infrastructure. Videos showed women and children waving flags as chanting blared on a loudspeaker.

Trump said on Truth Social: 'A whole civilization will die tonight, never to be brought back again. I don't want that to happen, but it probably will.' 

On Monday he threatened to target Iran's infrastructure, despite warnings that striking civilian energy and water supplies would constitute a war crime, as it is a clear breach of the Geneva Convention. 

Trump's envoy Steve Witkoff and Vice President JD Vance have been deeply involved in peace talks with Iran, with Pakistan playing a central role in mediating the negotiations.

Iran is officially led by Ayatollah Mojtaba Khamenei, appointed Supreme Leader after his father Ali Khamenei was killed in US-Israel strikes on February 28 - but he is unconscious and 'unable to be involved in any decision-making', a fresh intelligence memo states, raising urgent questions over who is actually running Tehran. 

Trump said in his Truth Social post: 'Now that we have Complete and Total Regime Change, where different, smarter, and less radicalized minds prevail, maybe something revolutionarily wonderful can happen, WHO KNOWS? 

'We will find out tonight, 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. God Bless the Great People of Iran!' 

The US struck approximately 50 military targets overnight on Kharg Island, Iran's crucial oil export hub, as fears mount over a potential ground invasion to seize it.

Bunkers, a radar station and ammunition storage were hit by US airstrikes, according to senior administration officials. Footage emerged on social media showing the aftermath of the destruction on the island. 

Senior Iranian officials rejected a temporary ceasefire proposal conveyed by intermediaries, Reuters reported, as the military action continued to escalate.

The Islamic regime showed no sign of agreeing to Trump's demand to reopen the Strait of Hormuz.

The passageway is a critical chokepoint through which roughly 20 to 25 percent of the world's seaborne oil passes. 

The President said Iran had until the end of Tuesday to restore access to the passageway or face strikes on civilian infrastructure, including bridges and power plants, in what would mark the biggest escalation of the war so far.