NEW YORK (AP) — Selena Gomez says her friend Francia Raisa saved her life by donating a kidney to the singer earlier this year.

Gomez and Raisa sat down for an interview with NBC News that is set to air next week. In a preview clip , Gomez says she didn't want to ask anyone to be a donor, but Raisa "volunteered and did it." Gomez announced the procedure last month, saying she needed a new kidney due to her struggle with lupus. Lupus is an autoimmune disease where the body mistakenly attacks its own tissues, sometimes including the kidneys.

She tells NBC her condition "was really kind of life or death."

The 29-year-old Raisa is an actress best known for her role on the ABC Family series "The Secret Life of the American Teenager."