Colbie Caillat and Justin Young have split up.

The Gone West bandmates - who got engaged in 2015 - have decided to go their separate ways after more than 10 years together but insisted their professional relationship won't change.

Colbie wrote on Instagram: ''This is difficult for us to share, but we want to be honest with you all. After 10 wonderful years, Justin and I have ended our relationship.

''We started out as best friends and we will continue to be best friends. And we will continue to work and make music together, as we always have.''

Colbie, 34, admitted ending their relationship and continuing to work together will be ''hard'' but she's confident they made the right choice.

She added: ''''It will be hard, but often times the hard choice is the right choice and the path that will allow each of us to move forward and to grow.

''We continue to be overwhelmed with gratitude for our love and time together.''

Justin, 41, shared a similarly-worded statement on his own Instagram account.

Last September, Colbie shared a touching photo montage of herself and Justin through the years to mark their 10th anniversary.

She captioned the Instagram post: ''10 years ago today (hot damn) on an afternoon in Paris @justinkawikayoung wrote me a cute n cheesy little note asking me to be his girlfriend, I circled yes *check out those dreads* (sic)''

The former couple got engaged on board a boat in May 2015.

Colbie revealed at the time: ''This sweet man asked me to be his lobster....and I said yes #colbieandchristina (sic)''