In the end, there was just not enough time to get things together. That’s what Christina Aguilera told fans in an open letter she posted on her website on Tuesday, explaining her decision to pull the plug on her already-announced summer tour in support of her upcoming Bionic album.

“I made the decision to move my summer tour and I am truly sorry to those of you who had purchased tickets and have been disappointed by the news,” Aguilera wrote. “Immediately after wrapping production on ‘Burlesque,’ I went directly back into the studio and then quickly started the promotional process for Bionic. With both the album press and film press, I am booked the entire summer and need time to focus on the work at hand. After reviewing the schedule with my team, I realized there was not enough time to put together and rehearse for a proper show, one that is at the caliber you expect from me or at the level I would present to my fans. In addition, my album has not even been released as yet, and I would like for you all to become familiar with the music before you hear it live on tour. Again, I am sorry to have to move the dates but I promise to come see you when the time is right!”

The tour’s promoter said the dates will be rescheduled for 2011, but no specific timetable has been given for when fans will see Aguilera hit the road again. The tour was slated to kick off on July 15 at the Mohegan Sun Arena in Uncasville, Connecticut, and wrap up on August 19 at the Verizon Wireless Amphitheater in Irvine, California, and was to feature opening act Leona Lewis. The singer’s first new album since 2006’s Back to Basics has gotten off to a modest start, with first single “Not Myself Tonight” peaking at #23 on the Billboard Hot 100. The accompanying transgressive video has stirred up controversy due to claims by Lady Gaga supporters that it borrows some of the reigning pop diva’s signature moves.

Your best chance to see Aguilera in the meantime is to tune in to Wednesday night’s “American Idol” finale and the June 6 MTV Movie Awards, where she is also scheduled to perform.