(CBS) George Michael's Symphonica tour has been brought to a halt in Europe due to the singer's ongoing battle with pneumonia.
Doctors say Michael, who's been hospitalized since last week, is responding to treatment and "slowly improving."
Dr. Christoph Zielinski and Dr. Thomas Staudinger of Medical University in Vienna, Austria, released a statement explaining, "George Michael has severe community acquired pneumonia and is being treated as an inpatient. His condition has stabilized and he is responding to treatment. From the current point of view, the time until recovery cannot be estimated, but he will not be able to perform the rest of the tour. Besides medical treatment, complete rest and peace and quiet are mandatory."
The former Wham! singer was taken to the hospital last week shortly before his concert in Vienna. Tabloid reports have suggested that Michael is suffering from a potentially fatal illness, but his spokeswoman dismissed the rumors.
Doctors advised Michael, 48, to "take a full and complete rest." His team sounds hopeful about a recovery and the rescheduling of tour dates. "George was very much looking forward to bringing his tour back home and performing for his loyal and dedicated UK fan base," explains a post on his website.
Michael has been performing with a full orchestra on his latest tour. Along with his own hits, he has been covering songs by The Police, Rihanna and Amy Winehouse.
Michael hasn't been active on Twitter since Nov. 17, when he wrote, "How am I doing so far?"