The Islamic State militant group said on Tuesday its second-in-command Fadhil Ahmad al-Hayali died in a US airstrike on the outskirts of the northern Iraqi city of Mosul.
IS spokesman Abu Muhammad al-Adnani confirmed the killing of al-Hayali, also known by his battle name Abu Muslim al-Turkmani, in an audio tape posted to jihadist websites.
The audio taped message also threatened Russia, which launched a campaign of military strikes against IS in Syria in late September.
It was not immediately possible to verify the authenticity of the audio tape.
Al-Hayali was in charge of IS's jihadist operations in Iraq.
The US government said on 21 August it was confident al-Hayali died in an August strike on vehicle driving near Mosul.
There had been several false reports of al-Hayali's death in the past.
He was an army colonel under Saddam Hussein and served in the regime's military intelligence and special forces units.
After the 2003 invasion of Iraq he joined the Sunni insurgency against Western forces and rose through the ranks of IS to become its leader Abu Bakr al-Baghdadi's deputy.
