US troops are ready to move into Afghanistan once the Northern Alliance captures a strategic town.
More than 1,000 US troops are ready for deployment after moving into Termez, near Uzbekistan's border with Afghanistan.
A US source in Tashkent said they are waiting to move once the Northern Alliance captures Mazar-i-Sharif, a large town some 30 miles south of the border.
Uzbekistan officials say they will not allow US troops to launch attacks in Afghanistan directly from its soil.
But the troops can use it as a dropoff for moving into areas held by the Northern Alliance, who are trying to take Mazar-i-Sharif.
In an interview with the RIA-Novosti agency, the Uzbek president's press secretary, Mr Rustam Jumayev, said Uzbekistan had made its airspace available to the US Air Force and allowed US transport aircraft and helicopters to land at one military base.
But Mr Jumayev said: "No permission has been granted for air strikes to be launched from Uzbek territory, nor for ground operations to be conducted against Afghanistan from this country".
AP