Iranian state media on Sunday confirmed that Supreme Leader Ali Khamenei was killed during joint U.S.-Israeli airstrikes, ending more than three decades of rule and triggering a 40-day national mourning period.

The announcement followed earlier claims by U.S. and Israeli officials that the 86-year-old cleric had died in the coordinated assault, which began early Saturday. Iranian outlets Tasnim and Mehr had initially reported that Khamenei remained “steadfast and firm in commanding the field,” but state media later confirmed his death.

U.S. President Donald Trump wrote on his Truth Social platform that Khamenei had been killed in the strikes, saying he was unable to evade American intelligence capabilities.

“He was unable to avoid our Intelligence and Highly Sophisticated Tracking Systems and, working closely with Israel, there was not a thing he, or the other leaders that have been killed along with him, could do,” Trump wrote.

Calling the moment “the single greatest chance for the Iranian people to take back their Country,” Trump added that he hoped the Islamic Revolutionary Guard Corps and the police would “peacefully merge with the Iranian Patriots.”

Khamenei had served as Iran’s supreme leader since 1989, succeeding revolutionary founder Ruhollah Khomeini, who led the 1979 Islamic Revolution that toppled the shah. As supreme leader, Khamenei wielded ultimate authority over Iran’s executive, legislative and judicial branches, as well as its armed forces, and acted as the country’s highest religious authority.

Following confirmation of his death, Iranian officials outlined an interim leadership arrangement. According to the official news agency IRNA, senior officials, including Ali Larijani, secretary of the Supreme National Security Council, said a temporary council comprising the president, the head of the judiciary and a cleric from the Guardian Council would assume the supreme leader’s responsibilities until a successor is chosen. Larijani said the mechanism would be implemented “as soon as possible” to ensure continuity of governance.

Among the potential successors frequently mentioned by analysts is Mojtaba Khamenei, the late leader’s son and a prominent figure within Iran’s clerical establishment.

Senior Iranian officials vowed swift retaliation. President Masoud Pezeshkian described Khamenei’s killing as a “declaration of war against Muslims” and warned that Iran considered it its “legitimate duty and right to avenge the perpetrators and masterminds of this historic crime.”

Larijani struck a similarly defiant tone, saying: “The brave soldiers and the great nation of Iran will teach an unforgettable lesson to the international oppressors.”

In a social media post echoing Trump’s combative style, he wrote: “Yesterday Iran fired missiles at the United States and Israel, and they did hurt. Today we will hit them with a force that they have never experienced before.”

As large crowds gathered in Tehran, explosions were reported in the capital, and the Israeli military said it was again striking targets in the city’s center. Blasts were also reported in Jerusalem, Riyadh, Dubai, Doha and Manama, underscoring the widening regional fallout from the confrontation.