Uzbekistan's Senate has approved the government's decision to evict US forces from a key base which Washington uses for operations in Afghanistan.
Last month the government reportedly gave the US six months to leave Karshi-Khanabad air base.
Relations with Washington were strained over the Uzbek authorities' bloody suppression of a protest in May.
Neighbouring Kyrgyzstan has also told the US it can no longer use one of its bases if the Afghan situation improves.
Washington's rivals for regional dominance, Russia and China, have made it clear they do not want to see US forces in the region on a permanent basis.
The Washington Post reported in July that the US had been given six months to move aircraft, personnel and military equipment from the base in southern Uzbekistan.
The eviction notice came days after US Defense Secretary Donald Rumsfeld returned from a visit to Uzbekistan's neighbours Kyrgyzstan and Tajikistan.
Mr Rumsfeld said he did not believe US operations in Afghanistan would be hurt if Tashkent denied continued use of its airbase, because there were other options in the region.
Flights into the Karshi-Khanabad (K2) base had already been reduced at the request of the Uzbek authorities, after the US criticised the government over events in Andijan.
Earlier this month, the US signalled that it might withhold $22m of aid to Uzbekistan, unless it allowed a full inquiry into the incident.
There are still disputed versions of exactly what happened on 13 May, when troops fired on a crowd of people.
Leading human rights groups say many hundreds of civilians were killed, with Human Rights Watch describing the incident as a "massacre".