ERBIL, Kurdistan Region of Iraq - US Central Command (CENTCOM) announced Friday that it has completed the transfer of Islamic State (ISIS) detainees from Syria to Iraq, asserting that "more than 5,700 adult male ISIS fighters" were moved as part of the process.

Iraq agreed to take in ISIS prisoners from its neighbor after the turmoil engendered by a January Syrian government offensive into Rojava (northeast Syria) raised fears that detention centers, previously operated by the Kurdish-led Syrian Democratic Forces (SDF), would be unable to maintain security amid the conflict.

Iraqi Prime Minister Mohammed Shia' al-Sudani termed it "an Iraqi decision made to preserve national, regional, and international security," with Baghdad cooperating closely with the US-led Global Coalition to Defeat ISIS during the transfer efforts.

CENTCOM, in the command's Friday statement, said that the transfer process was completed on Thursday and that coalition forces "led mission planning, coordination, and execution."

"The 23-day transfer mission began on Jan. 21 and resulted in US forces successfully transporting more than 5,700 adult male ISIS fighters from detention facilities in Syria to Iraqi custody."

"Job well done to the entire Joint Force team who executed this exceptionally challenging mission on the ground and in the air with great focus, professionalism, and collaboration with our regional partners," said CENTCOM commander Admiral Brad Cooper, who also expressed his appreciation for "Iraq's leadership and recognition that transferring the detainees is essential to regional security."

Iraq's justice ministry on Friday morning announced that 5,064 detainees have been received in the country, including 270 Iraqi nationals and over 3,000 Syrian citizens. The suspected members of the group are set to face judicial proceedings within Iraq, with Baghdad seeking to cooperate with other countries to ensure that foreign fighters are repatriated to their home nations.

"European countries are the most hesitant about repatriating their citizens from ISIS," said Foreign Minister Fuad Hussein in comments carried by state media, with many having proved hesitant over concerns regarding the reintegration of those with extremist ideologies and legal complications surrounding their prosecution for acts committed overseas.

Within Iraq, however, National Security Advisor Qasim al-Araji on Thursday stressed the importance of ensuring social inclusion for returnees. 

"The Iraqi experience has proven that true security is not built by force alone, but rather by thought, justice, equal opportunities, and social integration," said Araji.

Major General Kevin Lambert, the commander of the US-led Combined Joint Task Force – Operation Inherent Resolve (CJTF-OIR), said that "the successful execution of this orderly and secure transfer operation will help prevent an ISIS resurgence in Syria."

CENTCOM has repeatedly avowed its commitment to maintaining pressure on the group since its territorial defeat in Syria in 2019, announcing on Thursday that it has struck over 100 ISIS targets and killed more than 50 "terrorists" in the past two months.