The top US and Nato general in Afghanistan has formally transferred control as the US-led military mission fast approaches its end after 20 years.
General Austin "Scott" Miller stepped down on Monday, days after President Joe Biden said that US military operations would cease by 31 August.
Other Nato countries, including the UK, have withdrawn nearly all military forces ahead of Mr Biden's US deadline.
It comes as Taliban militants seize more territory throughout Afghanistan.
In a simple ceremony on Monday, Gen Miller handed over his duties to two US generals - one who will oversee US military action from Central Command headquarters in Florida, and one who will command the roughly 650 troops to remain after the official US withdrawal.
"It's important to me to say farewell," Gen Miller told the attendees, who included high ranking Afghan officials, in an emotional final address. "Our job is now not to forget."
Gen Miller was the longest serving officer to oversee Nato and US forces in Afghanistan, which he called "the highlight" of his career.
BBC chief international correspondent Lyse Doucet, who attended Monday's ceremony in Kabul, says his departure underscores how an era has ended - even as the US emphasises support will continue.
"It's going to be far harder for the US and its allies to know what's happening on the ground in Afghanistan, to have decisive impact in areas controlled by the government, and even less, in the growing number of districts where the Taliban now say they're in charge."
The Taliban recently claimed that their fighters have retaken 85% of territory in Afghanistan - a figure impossible to independently verify and disputed by the government. Other estimates say the Taliban controls more than a third of Afghanistan's 400 districts.
US-led forces removed the Taliban from power in 2001. The group had been harbouring Osama Bin Laden and other al-Qaeda figures linked to the 11 September 2001 attacks in the US that triggered the invasion.
President Biden and other US leaders have expressed confidence that the group will not topple the Afghan government in Kabul, though some intelligence analysts fear this could happen, according to an assessment distributed to officials in June.
After Monday's ceremony, Afghan National Security Adviser Hamdullah Mohib told reporters: "There will be no takeover."