Mojtaba Khamenei, the second son of Iran's Supreme Leader Ayatollah Ali Khamenei, now holds the most powerful seat in the country following a surprise election by the country's clerical body.
The official announcement made yesterday also called on Iranians to unite and support the new leadership.
According to a state media statement, Mojtaba's election was made through a vote described as "final," but no details about the process were disclosed.
The Council of Scholars also called on the elite, intellectuals and academic communities to pledge allegiance to the new leader at a critical juncture for Iran.
External support came from the Houthi group in Yemen, which hailed the appointment as a major victory for the Islamic Revolution and a major blow to the country's enemies.
However, the appointment sparked diplomatic tensions when US President Donald Trump publicly rejected the appointment, describing Mojtaba as an "unacceptable" candidate.
He also stressed that Washington would intervene in Iran's political direction if necessary.
Mojtaba's election marks the first time since the 1979 Islamic Revolution that Iran's supreme power has been inherited from generation to generation.
This raises serious questions about the future of a republican system that has long resisted dynastic and monarchical rule.
The death of Ali Khamenei in a US-Israeli attack on February 28 paved the way for this transition of power, which now enjoys strong support from core state institutions including the military and the Revolutionary Guard.
Although often behind the scenes and never holding any official position, Mojtaba's appointment now places him at a crossroads between preserving the revolutionary legacy or facing a political reality that the international community finds difficult to accept.
Israel has warned that it will continue to hunt down any successor to Ali Khamenei, signaling the possibility of increased confrontation in the region.
