"I'm very happy and proud of her", she said.
Despite knowing about her condition, Bieber keeps himself away from contacting Gomez.
The singer recently revealed she suffers from fibromyalgia, a disorder characterized by muscular pain accompanied by fatigue, sleep, memory and mood issues.
And the "Fetish" singer has also received support from her "close group" of friends.
Gomez, 25, wrote that she was "very aware" that many of her fans noticed she was out of the public's eye for parts of the summer.
Upon discovering pop-star Selena Gomez had undergone a life-saving kidney transplant, the 25 year old's former Disney Channel co-star, Jake T. Austin, has penned a heartwarming message to his "sister". "It was what I needed to do for my overall health". And finally, there aren't words to describe how I can possibly thank my lovely friend Francia Raisa.
Selena added that Francia gave her the "ultimate gift" and sacrifice by donating one of her key organs so Gomez can live and continue to work on her career. "I am incredibly blessed", added Gomez.
"Selena's openness and strong emotional connection to her worldwide audience has brought extraordinary awareness to a disease that is typically overlooked", the organisation's president, Kenneth M. Farber, says in a statement.
The "Hands to Myself" singer - who revealed in October 2015 that she was diagnosed with lupus and was undergoing chemotherapy for the autoimmune disease at the time - also shared that the donor was her longtime friend Francia Raisa, an actress best known for her role in The Secret Life of the American Teenager.
'I'm pumped for her.