"I didn't [know she had gotten the surgery]," Jonas confessed. "I was just as surprised as everyone else when I woke up and saw her Instagram, but wow. That's just incredible, and the strength she's shown through all of that is inspiring."
"I'm pumped for her. I'm happy to see she's doing well, it seems, and she was able to get the surgery and her friend helping her is a beautiful thing," he added. "So it's all amazing."
Jonas and Gomez dated during their Disney days from 2008 to 2010, but a source tells ET that it was her current boyfriend, The Weeknd, and her close group of friends who helped her through her recovery earlier this summer.
"This whole thing was more about her and the support of her girlfriends -- the ones in her very inner circle who have been with her since the beginning, like Francia," ET's source explained, adding that the experience brought her especially close to her kidney donor, Francia Raisa. "[Gomez] would have been perfectly happy keeping this private, but once it got out, they saw this as an opportunity to spread some positivity and shed light on donor transplants."
See more in the video below.