"It will probably be in Lhasa on June 18 but we are waiting to confirm that."
The Olympic torch had been scheduled to transit a district south of Lhasa on June 19 before spending the following two days in the Tibetan capital, where rioting against Chinese rule erupted in March.
The protests in March revealed deep anger against China's control of the devoutly Buddhist region, and overseas pro-Tibet activists have denounced the Tibetan leg - which was planned well before the unrest - as a further snub to local residents and world opinion.
The change is the latest made after tens of thousands of people were killed in the May 12 earthquake in Sichuan province.
The torch's worldwide relay is the longest and most ambitious in Olympic history. Following a one-month world tour in April, it is now on a three-month domestic circuit that has included taking a torch to the summit of Mount Everest.
However, since the flame was first lit in Greece on March 24, the relay has been repeatedly disrupted by groups trying to highlight grievances against China's communist rulers, especially their rule of Tibet.