Iran fired several missiles at countries in the Middle East hosting U.S. bases on Saturday.
A 40-day mourning period has been declared for Mr Khamenei.
Mr Khamenei was killed in his office after it was hit by missiles on Saturday.
The strikes by the U.S. and Israel have seen Iran’s Supreme Leader Ayatollah Ali Khamenei and top members of his regime dead.
“The world is a better place without them,” the IDF said.
Israeli Prime Minister Benjamin Netanyahu had said there were many signs Mr Khamenei had been killed in the strikes targeted against his residence.
The death of Mr Khamenei, 86, ends his reign of over three decades over Iran.
The Israeli prime minister said Israel, in collaboration with the U.S., coordinated the bombing of Iran on Saturday.
Earlier on Saturday, the U.S. and Israel launched deadly airstrikes on Iran.Â
On Saturday, the U.S. and Iran launched deadly airstrikes on Iran.
