Senior ISIS commander Omar Shishani died from injuries sustained in a recent US air strike in north-eastern Syria, the Pentagon has confirmed.
Earlier reports had suggested Omar Shishani, a Georgian whose real name was Tarkhan Batirashvili, may have survived the attack on a convoy.
Several of his bodyguards were killed in the same bombing.
The strike took place on March 4 near the north-eastern town of Shaddadi, where Omar Shishani had reportedly been sent to bolster local ISIS forces.
On March 13, monitoring group the Syrian Observatory for Human Rights said the ISIS leader had been “clinically dead” for several days.
In 2015, the US offered a $5 million reward for Omar Shishani.
It said he had held numerous senior military positions within the group, including “minister of war”.
Last week, the observatory’s director, Rami Abdul Rahman, quoted sources saying that Shishani had been badly wounded and had been taken to a hospital in Raqqa province where he was treated by “a jihadist doctor of European origin”.
US officials have said they believe Omar Shishani was sent to the Shaddadi area to reinforce ISIS militants following a series of military defeats.
Shaddadi was captured last month by the Syrian Arab Coalition, an alliance of Arab rebel groups which joined forces with the Kurdish YPG militia to battle ISIS.
Ten ISIS commanders have been killed in US-led coalition airstrikes in Iraq and Syria in the past month, a US military spokesman has said.
Some were linked to last month’s attacks in Paris and planning further attacks on the West, Col. Steve Warren added.
He named one as Charaffe al-Mouadan, who he said had a direct link to Paris attack cell leader Abdelhamid Abaaoud.
Another was a UK-educated Bangladeshi computer systems engineer, Col. Steve Warren said.
The US-led coalition has been targeting ISIS in Iraq and Syria for over a year. Russia recently began its own air attacks against armed opponents of the Syrian government, including ISIS.
Syria-based Charaffe al-Mouadan was killed in an airstrike on December 24, said Col. Steve Warren.
Another man with connections to the Paris attackers, Abdul Qader Hakim, died two days later in the northern Iraqi city of Mosul, he added.
Col. Steve Warren added that an earlier airstrike, on December 10, killed the UK-educated Bangladeshi computer engineer – who, he said, had supported ISIS hacking activities, anti-surveillance technology and weapons development.
“Over the past month we’ve killed 10 ISIL [ISIS] leadership figures with targeted air strikes, including several external attack planners, some of whom are linked to the Paris attacks,” he said.
“Others had designs on further attacking the West.
“As long as ISIL external attack planners are operating, the US military will hunt them and kill them.”
Abdelhamid Abaaoud, a Belgian national, was killed in a police raid in a Paris suburb just days after the November 13 attacks in the French capital which killed 130 people at multiple venues in the city. Most of the attackers also died.