Singer-actress Demi Lovato has announced plans for a 21-date North American concert tour to begin in June. Hot Chelle Rae and Owl City will be special guests on select dates of the concert series, which will kick off June 12 in Del Mar, Calif., Disney Music Group said Thursday. The tour to support her latest album, \"Unbroken,\" will wrap up Sept. 1 is Salem, Ore. Lovato, 19, is the former star of Disney Channel\'s \"Sonny with a Chance.\" Her career was temporarily sidelined about a year ago when she entered rehab to be treated for depression and eating disorders but she has since mounted a successful comeback. She recently finished a sold-out South American concert tour and her new single \"Give Your Heart a Break\" has gotten more than 10 million hits on YouTube.