Ke$ha has postponed her tour to continue treatment for an eating disorder.
The Tik Tok hitmaker entered rehab on January 3, and at the time released a statement indicating she would stay at the facility for 30 days.
But in a statement to MTV News, the 26-year-old pop star says she needs more time to focus on herself, and will remain at Chicago's Timberline Knolls Residential Treatment Center for an indefinite period.
"I was so looking forward to performing at these dates but I need to follow my doctor's advice and get my health back on track," she said.
"All of your support during this time has been so amazing. I couldn't have done this without you all. I look forward to coming back stronger than ever on the next tour."
Ke$ha was originally booked to perform in Hammond, Indiana on March 15 and in Green Bay, Wisconsin April 13, according to her website.
The star reached out to fans last month to thank them for their support.
"I just wanted to say that this is really hard and necessary work. I'm grateful for all the love and support,” she tweeted.
Ke$ha’s mother, Pebe Sebert, is meanwhile seeking treatment for post-traumatic stress disorder at the same facility alongside her daughter, checking in shortly after the star.
Pebe has openly accused music producer Dr. Luke of contributing to Ke$ha’s disorder, claiming he made cruel remarks towards the pop star.
Dr. Luke, real name Lukasz Sebastian Gottwald, has strenuously denied the claims.