Elton John has been forced to cancel a string of concerts after he was diagnosed with an E. coli bacterial infection and influenza.

The legendary British singer, 62, has been seriously ill for two weeks, but his condition worsened and he was taken into an elite London hospital on Friday for tests.

On doctor’s advice the “Rocketman” singer has postponed US tour dates in Seattle and Portland, where he was scheduled to perform with Billy Joel over the next two weeks.

“The Elton John/Billy Joel Face 2 Face concerts originally scheduled for Wednesday, November 4, Saturday, November 7, and Tuesday, November 10, have been postponed,” a spokesperson said. “Organizers are working to establish new dates.”