The number of United States troops in Afghanistan and Iraq has been reduced to 2,500 in each country.
In a statement on Friday, Acting US Defense Secretary Christoper Miller said the drawdown brings the number of US forces in Afghanistan to its lowest levels since 2001.
"Today, the United States is closer than ever to ending nearly two decades of war and welcoming in an Afghan-owned, Afghan-led peace process to achieve a political settlement and a permanent and comprehensive ceasefire," he said.
The announcement comes nearly two months after Mr Miller said the number of troops in Afghanistan would fall from around 4,500 to 2,500 and from 3,000 to 2,500 in Iraq.
Mr Miller said the US will "continue to execute" both the counter-terrorism mission and the training alongside NATO allies and partners in the country.
He added the US Department of Defense continues with planning "capable of further reducing US troop levels to zero by May of 2021", but that any future drawdowns remain "conditions-based".
"All sides must demonstrate their commitment to advancing the peace process," the statement continued.
The UK ended combat operations in Afghanistan in 2014 but still has 850 troops deployed on a NATO military training mission in the country.
In a separate statement about the reduction of troop levels in Iraq, Mr Miller said the drawdown is "reflective of the increased capabilities of the Iraqi Security Forces".
He said the force reduction in the country is in line with Operation Inherent Resolve’s transition from major combat.
"US and Coalition forces remain in Iraq to ensure the enduring defeat of ISIS [so-called Islamic State]," he said.
"The government of Iraq and the US government agree that ISIS remains a threat and that a US and Coalition presence remains vital."
In October last year, President Donald Trump said that US personnel in Afghanistan should be "home by Christmas" following the previous withdrawal of thousands of troops, while pledges were also made to remove servicemen and women from Iraq.
The British Army website says 400 UK military personnel are deployed to Iraq in a non-combat role, providing training to the Iraqi Security Forces and Kurdish Security Forces as part of a global coalition against so-called Islamic State.
Cover image: Library photo of US troops in Afghanistan (Picture: US Department of Defense).