He was targeted in US and Israeli strikes that killed his father and 40 members of the regime’s leadership, but survived. He is expected to remain a target of Israeli assassination attempts.

As Khamenei’s son, he carries dynastic legitimacy. Yet his appointment is not certain, because Iran has cracked down on succession in its leadership after the regime seized power in 1979.

Donald Trump said on Tuesday that “someone from within” the Iranian regime might be the best choice to take power once the US-Israel military campaign is completed.

The US president, who four days ago had called on Iranians to “take over your government” once the bombardment ended, appeared to drift further from the idea that the war presented an opportunity to end theocratic rule.

He told reporters in the Oval Office: “Most of the people we had in mind are dead. Now we have another group, they may be dead also, based on reports. So you have a third wave coming. Pretty soon we’re not going to know anybody.”

Reza Pahlavi, the exiled crown prince of Iran’s last shah, is positioning himself for a return to power should Iran’s Shiite theocracy fall.

Asked about Mr Pahlavi, Mr Trump said: “It would seem to me that somebody from within maybe would be more appropriate.” He adding that it may make sense for “somebody that’s there, that’s currently popular, if there is such a person” to emerge from the power vacuum.