The United States military says it has completed the withdrawal of all American troops from Iraq, ending the 12-year mission launched to fight the Islamic State group. The last forces left an air base in the northern Kurdistan Region under an agreement between Baghdad and Washington.

Pentagon spokesperson Sean Parnell described the departure as orderly and said it marked a transition from a wartime coalition mission to an Iraqi-led security effort supported by a more normal bilateral relationship. He said the United States would continue targeted training and intelligence support for Iraqi partners.

Baghdad presented the withdrawal as a milestone for sovereignty. But the security picture is not settled: officials in Iraq's Kurdish region have expressed concern about the loss of US air-defence systems and about the prospect of further attacks by Iran-linked armed groups.

The timetable was agreed two years ago, after the US presence had already been reduced. American forces returned to Iraq in 2014 at Baghdad's invitation to support the campaign against Islamic State after the group seized large areas of the country.

The departure also leaves Iraq facing an unresolved domestic question over non-state armed groups. Some militias have agreed to hand over weapons, but powerful groups close to Iran have resisted; the Iraqi government has pushed the target for disarmament to June 2027. The operational withdrawal is complete, but the political and security transition remains unfinished.