(Photo credit: Mike Coppola/Getty Images)

Selena Gomez fans who had been looking forward to her upcoming tour are out of luck.

The pop star announced that she will be canceling her tour dates in Asia and Australia.

"My fans are so important to me and I would never want to disappoint them," she said in a statement. "But it has become clear to me and those close to me that after many years of putting my work first, I need to spend some time on myself in order to be the best person I can be. To my fans, I sincerely apologize and I hope you guys know how much each and every one of you mean to me."

Gomez, 21, has had a busy year.

Not only did she spend much of 2013 on tour ( including a performance in Fairfax, Va. that went awry), but she also appeared in the films "Spring Breakers" and "Getaway," ended an off-again on-again relationship with Justin Bieber, and became a big sister.

"I'm 21, so now I've entered the decade of confusion about who I am and what I want to do with my life," she told Teen Vogue magazine. "That's what this entire decade's going to be."