Lisa Marie Presley's ex-husband and father of her twin daughters, Michael Lockwood, says her sudden death is "incomprehensible".
The 61-year-old musician and 14-year-old Harper and Finley are "all reeling" following the "unexpected tragedy", and Michael says making sure their girls feel "safe and loved" his his priority.
Michael began: "We are all reeling from the sudden passing of Lisa Marie Presley, the mother of my two beautiful twin daughters Harper and Finley.
"Nothing prepares us for such an unexpected tragedy. It is incomprehensible."
He added in a statement to People magazine: "The most important thing to me at this time is to take care of my daughters, making sure they always feel safe and loved.
"Both of them have incredible spirit and they will carry our family's legacy on for the rest of their lives. Since they were born, Harper and Finley have brought me profound joy and I remain devoted to them. We ask for privacy at this incredibly difficult time."
Elvis' only daughter passed away last week, aged 54, and her family confirmed the public have been invited to attend a service at her late father's Graceland mansion in Memphis, Tennessee, on January 22.
A statement on Graceland's official website read: "A memorial service for Lisa Marie Presley has been arranged for Sunday, January 22 at 9:00 am on the front lawn at Graceland Mansion in Memphis, Tennessee.
"General public is invited to attend. Please continue to check back to Graceland.com for additional details."
This comes after it was revealed Graceland - where music icon Elvis lived until his death in 1977, aged 42 - will stay in the Presley family.
The long-term future of the abode had been thrown into question following the passing of Lisa Marie, but a representative for Graceland confirmed that the property - which is in a trust - will benefit Lisa Marie's three daughters, Riley, 33, and Harper and Finley.
Lisa Marie also had a son named Benjamin, but he took his own life in 2020, aged 27.
Elvis' parents, Vernon and Gladys, and his grandmother, Minnie Mae, are all buried at the property. Elvis' twin brother, Jessie, who died at birth, and Lisa Marie's son are also buried at the landmark.