Halsey was a "massive fan" of Liam Payne.
The 30-year-old singer has admitted to being "deeply" hurt by the death of the former One Direction star.
Halsey wrote on Tumblr: "i loved one direction with an all-consuming force when i was younger. it hurts deeply to mourn someone you were a massive fan of as teenager, and became a peer of as an adult.
"i know people change and grief is unsure or complicated when it’s attached to a fond memory or the feeling a person gave you and not tangibly the person themself. i can see many of you on here are struggling with that right now and i understand. (sic)"
Halsey also shared details of one particular encounter with Liam, who died in Buenos Aires, Argentina on Wednesday (16.10.24), aged 31.
The 'Gasoline' hitmaker continued: "a few years ago i purchased a home that Liam previously owned. there were rumors the house was haunted. He assured me it was not, and i believed him. because i know the ghosts that haunt us aren’t tethered to buildings. They live in parts of us that are harder to reach and they go wherever we do.
"as a parent, a fellow artist, and a fan, i simply cannot fathom this untimely loss. my heart goes out to his family, friends, and the fans. [broken-heart emoji] (sic)"
Liam died after falling from the third floor of the Casa Sur Hotel.
His family subsequently paid tribute to Liam, describing him as a "kind, funny and brave soul".
They said in a statement: "We are heartbroken. Liam will forever live in our hearts and we’ll remember him for his kind, funny and brave soul.
"We are supporting each other the best we can as a family and ask for privacy and space during this awful time."