Pop star Demi Lovato will always be "best of friends" with her ex-boyfriend Wilmer Valderrama, despite calling off their six-year romance last summer (16).

The Cool For The Summer hitmaker took to Instagram on Saturday (10Jun17) to share a snap of the two exes reunited.

"Best of friends no matter what," she captioned the photo of the smiling pair cuddling up.

Demi, 24, and Wilmer, 37, broke the news of their split to fans in a joint statement on social media a year ago, when they came to the conclusion they were "better as friends" than lovers.

"We will always be supportive of one another," the stars continued. "Thank you to everyone who has offered us kindness and support over the years. With only love, Wilmer & Demi."

Demi later admitted her romance with the That '70s Show actor was a constant reminder of her previous substance abuse and mental health battles, which she wanted to leave firmly in her past.

"I think it's healthy to be able to start over with someone else," the sober singer told Glamour magazine months later. "Being sick was always a part of my relationship with him; I always had something wrong with me. I needed to let go of that. It was hard to depart from somebody who saw everything, but it may be nice to start fresh with somebody. Because that person I was when I was a lot younger is not who I am today."

Since parting ways in June, 2016, Demi has been linked to mixed martial arts fighters Luke Rockhold and Guilherme Vasconcelos, who she broke up with in early May (17) after going public with their romance in December (16).

Wilmer, meanwhile, was most recently reported to have rekindled his relationship with actress Minka Kelly, who he is said to have first dated in 2012.