Iran's ruling clerics on Sunday appointed the slain leader's son, Ayatollah Mojtaba Khamenei, as the country's new supreme leader, defying threats from the United States and Israel to oppose him.

Nine days after US-Israeli strikes killed the elder Ayatollah Ali Khamenei and plunged the Middle East into war, the clerical government's Assembly of Experts convened to choose their next leader.

Mojtaba Khamenei, 56, "is appointed and introduced as the third leader of the sacred system of the Islamic Republic of Iran, based on the decisive vote of the respected representatives of the Assembly of Experts," the clerical body said in a statement.

It said that the clerical body "did not hesitate for a minute" in choosing a new leader, despite "the brutal aggression of the criminal America and the evil Zionist regime."

Shortly afterwards, Iran's Revolutionary Guards pledged allegiance on to the new supreme leader.

"The Islamic Revolutionary Guard Corps... is ready for complete obedience and self-sacrifice in carrying out the divine commands of the Guardian Jurist of the time, His Eminence Ayatollah Seyyed Mojtaba Khamenei", the Guards said in a statement.

The announcement came after Tehran signalled defiance, despite US President Donald Trump's call for an "unconditional surrender."

Mohammad Bagher Qalibaf, Iran's parliament speaker, said earlier that Tehran was not seeking a ceasefire to the war and would punish aggressors.

Trump has previously dismissed the younger Khamenei as a "lightweight," and insisted again on Sunday that he should have a say in the new leader's appointment.

"If he doesn't get approval from us he's not going to last long," he told ABC News before the announcement was made.

But Tehran's top diplomat said on Sunday that the decision was Iran's alone, adding it would "allow nobody to interfere in our domestic affairs."

Speaking on NBC's "Meet the Press", Foreign Minister Abbas Araghchi also demanded Trump "apologise to people of the region" for starting the war.

The younger Khamenei is regarded as a conservative figure, notably because of his ties with the Revolutionary Guards, the ideological arm of the Islamic republic's military.

Israel's military had previously warned any successor that "we will not hesitate to target you." (AFP)



Edited by Cecil Wong