Demi Lovato is ''proud'' of Selena Gomez following her recent kidney transplant.

The 25-year-old singer recently admitted to undergoing the life-saving operation after her battle with autoimmune disease Lupus - in which the body attacks healthy cells - had caused the health of her organs to deteriorate, and her close pal Demi has now praised her as a ''strong woman''.

Speaking to People magazine, the 'Sorry Not Sorry' hitmaker said: ''I think that she is a very strong woman. I'm very happy and proud of her.''

Demi, also 25, isn't the only celebrity to have wished Selena all the best with her recovery either, as 'Jealous' musician Nick Jonas - who previously dated the star from 2008 to 2010 - said he was ''inspired'' by the strength she has shown in the face of her condition.

He said recently: ''I didn't [know she had gotten the surgery]. 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. So it's all amazing.''

Selena revealed the details of her kidney transplant in a lengthy Instagram post on Thursday (14.09.17), in which she claimed her recovery was the reason she laid low over the summer.

She wrote: ''I'm very aware some of my fans had noticed I was laying low for part of the summer and questioning why I wasn't promoting my new music, which I was extremely proud of. So I found out I needed to get a kidney transplant due to my Lupus and was recovering. It was what I needed to do for my overall health. I honestly look forward to sharing with you, soon my journey through these past several months as I have always wanted to do with you. ''Until then I want to publicly thank my family and incredible team of doctors for everything they have done for me prior to and post-surgery. And finally, there aren't words to describe how I can possibly thank my beautiful friend Francia Raisa. She gave me the ultimate gift and sacrifice by donating her kidney to me. I am incredibly blessed. I love you so much sis. Lupus continues to be very misunderstood but progress is being made. For more information regarding Lupus please go to the Lupus Research Alliance website: (sic)''