Tehran, Iran - Israeli strikes killed the intelligence chief of Iran's Revolutionary Guards, as the Islamic republic on Monday defied threats from US President Donald Trump to devastate civilian infrastructure if it does not reopen the Strait of Hormuz.

Iran's Revolutionary Guards posted on Telegram Monday that their intelligence chief Majid Khademi had been killed "at dawn" in US-Israeli strikes.

Israel's Defence Minister Israel Katz said his country's military had been behind the strike, saying that it had been a response to Iran's attacks on civilian areas in Israel.

Katz called Khademi "one of the direct perpetrators of these war crimes and one of the top three officials in the organization," and said of Iran's leaders: "We will continue to hunt them one by one."

The warring sides kept up their barrage of strikes, with Iranian missiles and drones targeting Israel, Kuwait, and the United Arab Emirates, and Israeli strikes hitting Iran and swathes of Lebanon.

Iran said that "much more devastating" attacks would come if Trump followed through on his vow to hit civilian targets.

The American leader had in social media posts Sunday threatened to destroy Iran's civilian infrastructure if Tehran does not bow to his demand to reopen the Gulf to shipping by "Tuesday 8:00 PM."

Iran has all but blocked the Strait of Hormuz, a vital energy chokepoint, sending oil and gas prices soaring and pushing countries around the world to enact measures to contain the fallout.

In a stark, expletive-laden post on Sunday, Trump demanded: "Open the F***in' Strait, you crazy bastards, or you'll be living in Hell."

Tehran's Deputy Foreign Minister Kazem Gharibabadi responded to Trump's by saying that the US leader had "publicly threatened to commit war crimes" by menacing bridges and power plants.

Iran's Revolutionary Guards said the strait "will never return to its former status, especially for the US and Israel."

Citing US, Israeli, and regional sources, Axios said a deal mediated by Pakistan, Egypt, and Turkey for a 45-day ceasefire to allow for negotiations on a more permanent peace was under discussion.

Egypt's Foreign Minister Badr Abdelatty had on Sunday confirmed he was engaging in talks with governments across the region, as well as US envoy Steve Witkoff and Iran's Foreign Minister Abbas Aragchi.

"Views and proposals were exchanged on ways to deescalate the military situation in the region given the delicate juncture it is currently facing," a statement from the ministry said.

Trump told Fox News Iran was "close" to making a deal, but Iran has repeatedly denied it was engaged in any negotiations with the US and Israel.