He was killed in a coalition drone strike last month in Baghouz, the village in eastern Syria where diehard ISIS fighters are making a bloody last stand.
In Washington, Pentagon spokesman Commander Sean Robertson said that in addition to the almost 1,000 foreign fighters held by the SDF, there were thousands of other suspected Islamic State militants from Iraq and Syria held by the USA -backed group.
The evacuations came as the US-backed forces slowed down their latest push on Baghouz, the last shred of ISIL-held territory, to allow civilians to leave the tiny enclave.
An SDF official told AFP "hundreds" of ISIS fighters were among them.
With the militants besieged on three sides by the SDF and civilians continuing to leave the pocket, a military defeat of the IS fighters seemed inevitable, though it wasn't clear how many fighters remained in Baghouz.
The militants and their families and other civilians are believed to have used tunnels, caves and holes to hide from airstrikes and missiles by the US -led coalition and the SDF.
Some 283 prisoners suspected of being affiliated to Daesh have been released by the Syrian Democratic Forces (SDF) over the weekend as a gesture of "cooperation, fraternity and clemency", the group said in a statement.
The Kurdish-led force pushed into Baghouz on Saturday. Six were sent to hospital.
Around 15,000 people reached the Al-Hol camp from Baghouz between February 22 and March 1, the United Nations humanitarian coordination office OCHA said on Monday. According to the OCHA, around 90 people, mostly children under the age of five, have died en route to the shelter or shortly after arriving.
The government has declared that Hoda Muthana, 24, is not an American citizen, and has barred her from entry.
The war is in its final days, officials say.
The Kurdish-led forces launched their broad offensive on remaining IS strongholds in the Euphrates Valley six months ago.
While the capture of Baghouz would mark a milestone in the fight against IS, the group is expected to remain a security threat as an insurgent force with sleeper cells and some pockets of remote territory.