The US military pulled out of a strategic district in eastern Afghanistan on Saturday as part of a deal with President Hamid Karzai, who alleged that soldiers had mistreated locals.
Karzai had at first accused Afghan militia working with elite US units of torturing and murdering civilians, but later changed his allegations to focus on unproven claims of "harassment" by American troops.
The president issued an ultimatum that US commandos leave the province of Wardak, a key region close to the capital Kabul, raising concern that the pullout would create a major security opening for Taliban insurgents.
A compromise deal was reached in which US troops would leave Nerkh, one of Wardak's eight districts, as the US and Karzai tried to smooth over a series of damaging public rows.
"Our forces have transitioned Nerkh district to Afghan National Security Forces and they have now assumed full responsibility for security in this key district," General Joseph Dunford, commander of the US-led coalition, said.
"The rest of Wardak will continue to transition over time as Afghan forces continue to grow in capability and capacity," he added in an emailed statement.
Relations between Karzai and Washington were badly frayed recently as the bulk of NATO's combat soldiers get ready to leave by the end of next year.
The United States, which provides 66,000 of the 100,000 total troop deployment, was stunned by Karzai's accusations earlier this month that the US worked in concert with the Taliban to justify its presence in the country.
The Afghan president's spokesman also described the coalition war effort against the Taliban as "aimless and unwise".