Listen: Marshmello + Halsey release 'Be Kind'.

Halsey has teamed up with Marshmello to release 'Be Kind', a song Halsey describes as a "cute optimistic heartfelt dance summery 80s" song.

In the song, Halsey sings about wanting honesty in a relationship, singing, "When you know you can cry / To the one, always confide / In the one, you can be kind too / The one that you love."

About the song, Marshmello says: “As soon as we finished the song, I was instantly obsessed! Halsey and I connected and were both on the same page with what we wanted the final outcome to be! And it turned out great.”

Listen to 'Be Kind' below...