Uzbek President Islam Karimov has rejected calls for an international inquiry into a bloody crackdown on protesters last week.
The real death toll may never be known
Mr Karimov ruled out an investigation into events in the town of Andijan during a phone conversation with UN Secretary General Kofi Annan.
Uzbekistan has said 169 people died, but an army source told the BBC 500 people were killed in the protest.
The US has announced that it is scaling back operations at its Uzbek airbase.
Mr Annan said Mr Karimov had told him "he did not need an international team to establish the facts".
Most populous central Asian former Soviet republic, home to 26m people
Ruled since 1991 independence by autocrat Islam Karimov
Accused by human rights groups of serious abuses, including torture
Rocked by violence in capital Tashkent in 2004
Government says radical Islamic groups behind violence
"[President Karimov] said he had the situation under control and was taking every measure to bring those responsible to account," said Mr Annan.
Mr Karimov's regime has come under increasing international pressure in the wake of the incident.
US presidential spokesman Scott McClellan reiterated White House calls for "a more open and responsive government".
Washington has close links with Uzbekistan, and has an airbase in the south of the country which provides logistical support to operations in Afghanistan.
The head of US Central Command, General John Abizaid, said on Thursday that the US military was limiting its operations at the base as a "prudent move" due to the recent violence.
But he said this was not intended to be a political message of disapproval to President Karimov.
The unrest in Andijan began when a group of men stormed the town's prison and freed 23 businessmen accused of being Islamic extremists.
These men joined a large protest, which correspondents say was also fuelled by long-term frustration over poverty and unemployment.
Locals say troops then fired indiscriminately into the crowd.
The authorities say no civilians were killed, only Islamic militants who had organised the protest.
Troops on Thursday retook control of the border town of Korasuv, where locals had seized control from government officials following the events in Andijan.
Although a number of explosions and some gunfire was heard, the takeover of the eastern town seemed to have been largely peaceful.
The uprising's leader in Korasuv, Bakhtior Rakhimov, who said he intended to build an Islamic administration in the town, has been arrested.