Iggy Azalea arrives at the iHeartRadio Music Awards at The Forum on Sunday, March 11, 2018, in Inglewood, Calif. Picture: AP

Iggy Azalea is "proud" of Demi Lovato for her honest new song, 'Sober', and offered her friend support in her continued recovery from addiction.

The 'Savior' rapper praised her friend - who celebrated being sober for six years in March - for opening up about a relapse in her addiction struggle in 'Sober', and offered her support as the 25-year-old star continues her battle through recovery.

READ: Demi Lovato opens up about breaking her sobriety in emotional song 'Sober'

Iggy tweeted: "Waking up listening to @ddlovato 'sober'. I'm proud of you for having the guts to reveal your truth to the world again. NOT EASY. I'm here for you friend! (you know this) I pray you'll choose recovery again. All of us who love you only want to see you happy and healthy.(sic)

Demi revealed the track on Thursday (21.06.18), when she tweeted a lyric video, which features candid pictures of her as a child and adult, and wrote: "My truth..."

On the track, Demi sings: "Mama, I'm so sorry I'm not sober anymore, and Daddy please forgive me for the drinks spilled on the floor.

"To the ones who never left me, we've been down this road before. I'm so sorry, I'm not sober anymore."

She later apologises to her fans, and admits while she would like to be a good example for them she is "only human".

She croons: "And I'm sorry for the fans I lost who watched me fall again. I wanna be a role model but I'm only human."

The 'Skyscraper' hitmaker has been open about her battle with addiction - and her stint in rehab in 2010 - and emotionally celebrated her six year milestone during a concert in March.

The following month, she was snapped drinking from a red cup at Hayley Kiyoko's album release party - but she was quick to shut down her critics who doubted her sobriety.

She replied on social media: "I don't have to defend anything but it was red bull."