A US military airstrike reportedly took out the self-proclaimed Islamic State's second-in-command in Iraq earlier this week, according to US officials.

Fadhil Ahmad al-Hayali — or Haji Mutazz, as he is more commonly known — died in an August 18 strike near the Iraqi city of Mosul, US National Security Council (NSC) spokesman Ned Price said in a statement on Friday.

Hayali was a former al Qaeda in Iraq member who served most recently as the senior deputy to IS leader Abu Bakr al-Baghdadi, leading operations for the militant group in Iraq and Syria. He allegedly played a major role in trafficking weapons, explosives, vehicles, and people between the two countries, where IS has secured large swathes of land since June 2014.

"He was instrumental in planning operations over the past two years, including the ISIL offensive in Mosul in June 2014," Price said today. "Al-Hayali's death will adversely impact ISIL's operations given that his influence spanned ISIL's finance, media, operations, and logistics."

Hayali was said to have been driving in a vehicle near Mosul with a media operative who went by the name Abu Abdullah, who was also killed in the airstrike. The White House did not disclose the exact location of the strike.

Reports that Hayali had been killed first emerged in December of 2014, which claimed that he was one of three IS officials killed by US-led coalition airstrikes. The information came through senior military officials cited in outlets like CNN. There was no reference to the earlier reports in Price's statement on Friday.

The news of Hayali's death comes one year since the US-led bombing campaign against IS, known as Operation Inherent Resolve, began. Since last summer, the coalition has carried out more than 6,000 airstrikes in Iraq and Syria. The aim of the campaign, according to the Pentagon, is to "degrade and ultimately destroy" the organization.