"They have not officially handed over the base to us but I can confirm they left the base on Wednesday," said Khoja Yaya Alawi, a spokesman for the Afghan army in Kandahar.
"They have handed over all the facilities to Afghan forces," Massoud Pashtun, the director of Kandahar Airport, added.
An official handover is expected to take place after the Muslim holiday of Eid Al-Fitr, which ends on Saturday, both officials said.
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At its height, the airfield was the second largest base for US and international troops.
Kandahar province was the birthplace of the Taliban and has in recent months seen intense clashes between militants and Afghan forces.
The Taliban and Afghan forces are currently in the middle of a three-day ceasefire which has granted respite for Afghans across the country as they celebrate the Muslim holiday.
The US military did not immediately comment.
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