Iran forms interim leadership and vows retaliation after Khamenei’s killing in attacks blamed on the U.S. and Israel.Tehran declares mourning and warns of major reprisals after the Supreme Leader was martyred in attacks attributed to the United States and Israel.Iran announced the formation of an interim leadership council on Sunday following the killing of Supreme Leader Ayatollah Ali Khamenei during attacks attributed by Iranian authorities to the United States and Israel.Acting President Mohammad Mokhber stated that a transitional council made up of President Masoud Pezeshkian, Judiciary Chief Gholamhossein Mohseni Ejei, and a jurist from the Guardian Council will assume leadership duties during the transition period after Khamenei’s death. The measure was reported by the state news agency IRNA.The Iranian government also declared 40 days of national mourning and announced a week-long suspension of work activities following what officials described as the assassination of the leader of the Islamic Revolution.According to Ali Larijani, the formation of the Interim Leadership Council will take place today. He confirmed that the groundwork was laid during a meeting yesterday, and the council is set to be formed as of now. pic.twitter.com/trNifSvAJ0— IRNA News Agency ☫ (@IrnaEnglish) March 1, 2026According to Iranian state media, Khamenei was killed early Saturday inside his office during strikes targeting Tehran and other cities across the country. Hours before Tehran officially confirmed the death, U.S. President Donald Trump and Israeli Prime Minister Benjamin Netanyahu had publicly announced that the Iranian leader had died.Leader of Iran, Sayyed Ali Khamenei, Martyred in US-Israeli AggressionFollowing confirmation of the killing, Iran’s Islamic Revolutionary Guard Corps (IRGC) pledged retaliation, warning of a “harsh and decisive” response through what it described as the largest military operation in its history against U.S. and Israeli targets.“We have lost our great leader and we mourn him (…) His martyrdom at the hands of the most terrible terrorists and exterminators of humanity is a symbol of his virtue,” the Revolutionary Guard said in an official statement.The Iranian Revolutionary Guard Corps pledges revenge and says it has launched attacks on 27 bases hosting US troops in the Middle East, as well as Israeli military facilities in Tel Aviv. 🔴 LIVE updates ⤵️ https://t.co/Tz6nQiIF3Y— Al Jazeera English (@AJEnglish) March 1, 2026The leadership transition unfolds amid rapidly escalating regional tensions following the killing of Iran’s highest political and religious authority. (teleSUR)