American troops have left Iraq after more than two decades, closing one of the longest and costliest chapters in US military history.

The withdrawal follows a 2024 agreement between Washington and Baghdad, implemented under the Trump administration. About 4,500 American service members lost their lives since the 2003 invasion.

Iraq’s government declared a two-day public holiday to mark what it called a historic restoration of sovereignty. Prime Minister Mohammed Shia al-Zaidi said the moment belonged to the Iraqi people.

The pullout coincides with a September 30 deadline for Iran-aligned militias to disarm, a condition that has seen little compliance. Analysts warn the militias could fill the security vacuum left behind.

Washington says the relationship will now shift to bilateral security cooperation, including intelligence sharing and military training. The region watches closely to see how the balance of power evolves. Veterans’ groups in the US have called for renewed support for those who served in the long conflict.