The top US commander in Afghanistan has relinquished his command at a ceremony in the capital Kabul, taking the US a step closer to ending a 20-year military presence that became known as its "forever war."
The move comes as Taliban insurgents continue to gain territory across the country.
General Scott Miller handed over command to Marine General Frank McKenzie, the head of US Central Command.
McKenzie, also a four-star general, will operate from Central Command headquarters in Tampa, Florida.
McKenzie assumes authority to conduct possible airstrikes in defence of Afghan government forces, at least until the US withdrawal concludes by August 31.
Miller, who commanded US troops in Afghanistan since 2018, is to leave the country later on Monday.
The handover took place at a time of rapid territorial gains by Taliban insurgents across Afghanistan, mainly rural areas in the north.
The Afghanistan National Defence and Security Forces, mostly funded by the United States and NATO, have put up resistance in some parts of the country, but overwhelmingly Afghan government troops appear to have abandoned the fight.
In recent weeks, the Taliban have gained several strategic districts, particularly along the borders with Iran, Uzbekistan and Tajikistan.
The Taliban control more than one-third of Afghanistan's 421 districts and district centres. A Taliban claim that they control 85 per cent of the districts is widely seen as exaggerated.
After Miller's departure, a two-star admiral based at the US Embassy in Kabul will oversee the US military's role in securing the American diplomatic presence in Kabul, including defending the Kabul airport.