US troops will leave their base in Uzbekistan by the end of the year, a senior US diplomat has confirmed.
The Uzbek base has been a key hub for US troops
Assistant US Secretary of State Daniel Fried, speaking after talks in Tashkent, said the US had agreed to the demand "without further discussion".
He admitted bilateral ties had gone through a "very difficult period" after the US criticised Uzbek suppression of an uprising in Andijan in May.
But he dismissed as "ludicrous" claims that the US had been behind the unrest.
The airbase at Karshi-Khanabad in south-eastern Uzbekistan has been an important hub for US operations in neighbouring Afghanistan following the 11 September 2001 attacks.
"The Uzbek government made it clear that we need to leave the base, and we intend to leave it without further discussion," said Mr Fried after meeting Uzbek President Islam Karimov.
He said the two countries' interests in security and democracy "are indivisible" but conceded "we did not agree on some issues".
"The United States and Uzbekistan have had a very difficult period in relations, complicated by grave concerns regarding the human rights situation and events in Andijan".
Fifteen men are currently on trial accusing of leading the popular protests in Andijan. They face multiple charges, including terrorism, shooting hostages and belonging to banned Islamic groups.
All have pleaded guilty. Human rights groups allege the confessions were elicited through torture.
One defendant said on Monday that the US embassy in Tashkent had given him money to help organise the violence - dismissed by Mr Fried as "ludicrous".
"The assertions that the US supports an attack by Islamic extremists after fighting four years against exactly such people is not credible," he said.
The unrest began on 12 May after supporters of 23 local businessmen - on trial for alleged Islamic extremism - broke into Andijan's jail and freed them.
The armed men then occupied the town hall and a huge anti-government protest began.
Witnesses say more than 500 people were killed by Uzbek security forces in the crackdown that followed.
The Uzbek government put the death toll at 187, and has rejected demands for an international investigation into the incident.