Donald Trump has said the death of Virginia Giuffre, who accused Prince Andrew of sexual assault, is "a horrible thing".
Her family said Ms Giuffre "lost her life to suicide" at her farm in Western Australia on Friday, aged 41.
And responding to a reporter's question at a New Jersey airport, the US president said: "That whole situation is very sad - her and others.
"Certainly, that's a horrible thing."
On Monday, a Western Australia Police spokeswoman confirmed Ms Giuffre's death was still under investigation, but did not appear to be suspicious.
Ms Giuffre sued the Duke of York for sexual abuse in August 2021.
The duke has repeatedly denied the claims and has not been charged with any criminal offences.
In March 2022, it was announced Ms Giuffre and Prince Andrew had reached an out-of-court settlement.
American-born Ms Giuffre was one of the most outspoken accusers of convicted sex offenders Jeffrey Epstein and his former girlfriend Ghislaine Maxwell.
She became an advocate for survivors of sex trafficking after emerging as a central figure in the prolonged downfall of Epstein, who was a financier.
In subsequent civil lawsuits, Ms Giuffre said she was a spa attendant as a teenager at Mar-a-Lago - Mr Trump's Palm Beach club - when she was approached in 2000 by Maxwell.
Ms Giuffre was hired as a masseuse for Epstein and was flown around the world for meetings with men at his behest while she was 17 and 18.
Maxwell, the British socialite, was convicted in 2021 on federal sex trafficking and conspiracy charges and was sentenced to 20 years in prison.
Ms Giuffre alleged she was trafficked to Prince Andrew when she was 17, a claim he has denied.
Her family said in a statement that Ms Giuffre was a "fierce warrior in the fight against sexual abuse" but that the "toll of abuse… became unbearable".
:: Anyone feeling emotionally distressed or suicidal can call Samaritans for help on 116 123 or email jo@samaritans.org in the UK. In the US, call the Samaritans branch in your area or 1 (800) 273-TALK.
(c) Sky News 2025: Trump says death of Virginia Giuffre, who accused Prince Andrew of sexual assault, is 'a
Israel is 'starving, killing and displacing' Gaza civilians, Palestinian envoy tells UN court
Date set for conclave to decide next pope - here's how the secretive process works
Canada might be the second election Trump wins in six months
Why Crimea is so important to Russia and Ukraine
Man charged with murder after 11 killed in Vancouver vehicle attack
Trump 'very disappointed' in Russian strikes on Ukraine and calls for Putin to 'sit down and sign a deal'
Kim Kardashian's Paris robbery trial: Everything you need to know
At least 68 killed in US airstrike on Yemen jail holding African migrants, Houthi rebels say
Pilgrims travel to Pope Francis's tomb to remember the late pontiff
