Beirut (AFP) - The Islamic State group's spokesman confirmed on Tuesday the killing of the jihadist organisation's second in command in a US air strike earlier this year.

"America is rejoicing over the killing of Abu Mutaz al-Qurashi and considers this a great victory," Abu Mohamed al-Adnani said in an audio recording posted on jihadist websites.

"I will not mourn him... he whose only wish was to die in the name of Allah... he has raised men and left behind heroes who, God willing, are yet to harm America," he added.

Adnani did not say, however, in what circumstances Qurashi died.

But the White House, in an announcement on August 22, said that Qurashi, whose real name is Fadhil Ahmad al-Hayali, was killed on August 18 in a US air strike near the northern Iraqi city of Mosul.

It said the strike targeted a vehicle and also killed an IS "media operative" known as Abu Abdullah.

The US National Security Council said at the time that Hayali was IS leader Abu Bakr al-Baghdadi's senior deputy.

The White House described Hayali as a member of the IS ruling council, and "a primary coordinator for moving large amounts of weapons, explosives, vehicles and people between Iraq and Syria".

IS controls large swathes of Syria and neighbouring Iraq and has set up an Islamic "caliphate" straddling both countries.

In its August announcement the White House also said that Hayali "was in charge of ISIL operations in Iraq, where he was instrumental in planning operations over the past two years, including the ISIL offensive in Mosul in June 2014," using another name for IS.

Like many senior Iraqi jihadists, before joining the IS group, Hayali had been a member of Al-Qaeda's Iraqi faction.

He was reportedly a former Iraqi officer from the era of Saddam Hussein.

IS militants launched a devastating offensive in Iraq in June 2014.

Beginning in Mosul, the country's second city and capital of Nineveh province, they swept security forces aside and eventually overran around a third of the country.