Prince Andrew has provided "zero cooperation" to American investigators who want to interview him as part of their sex-trafficking probe into convicted sex offender Jeffrey Epstein, a US prosecutor says.

Key points: Numerous women say they were sexually abused by Epstein as teenagers

Numerous women say they were sexually abused by Epstein as teenagers The US Attorney-General has vowed to charge anyone who helped Epstein

The US Attorney-General has vowed to charge anyone who helped Epstein A woman alleges she had several sexual encounters with Prince Andrew at Epstein's behest, starting when she was 17

Speaking at a news conference outside Epstein's New York mansion, US federal attorney Geoffrey Berman said prosecutors and the FBI had contacted Prince Andrew's lawyers and asked to interview him.

"To date, Prince Andrew has provided zero cooperation," Mr Berman said.

Buckingham Palace has been approached for comment.

In the statement released in November, Prince Andrew said he regretted his "ill-judged association with Jeffrey Epstein".

"Of course, I am willing to help any appropriate law enforcement agency with their investigations, if required," he wrote.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 40 seconds 1 m 40 s Prince Andrew said he would give a statement under oath regarding Epstein.

Prince Andrew announced last year he was withdrawing from his Royal duties amid renewed public attention on a woman's accusation she had several sexual encounters with him at Epstein's behest, starting when she was 17.

Prince Andrew with Virginia Roberts (middle) and Ghislaine Maxwell (right) in a 2001 photo. ( Supplied )

Virginia Roberts Giuffre said after meeting Epstein in Florida in 2000, the millionaire flew her around the world and pressured her into having sex with numerous older men, including Prince Andrew, two senior US politicians, a noted academic, wealthy financiers and the attorney Alan Dershowitz, who is now part of US President Donald Trump's impeachment defence team.

All of those men have denied the allegations.

Epstein killed himself in his jail cell last year while he was awaiting trial on sex trafficking charges.

"Jeffrey Epstein couldn't have done what he did without the assistance of others, and I can assure you that the investigation is moving forward," Mr Berman said.

Ms Giuffre said she had sex with Prince Andrew three times, including once in London in 2001 at the home of Epstein's girlfriend, Ghislaine Maxwell.

Numerous women who said they were sexually abused by Epstein as teenagers alleged in lawsuits and interviews he got help recruiting young girls from both Ms Maxwell and several assistants.

Prince Andrew and Ms Maxwell have both denied knowing that Epstein was sexually abusing teenage girls.

In a TV interview last year, Prince Andrew insisted he was out having pizza with his children on the night Ms Giuffre said they were together in London.

US Attorney-General William Barr has vowed to aggressively investigate and bring charges against anyone who may have helped Epstein.

Prince Andrew has said he regrets his "ill-judged association with Jeffrey Epstein". ( AP: Sang Tan )

AP