Joe Biden's son Hunter pleaded guilty in his tax evasion trial on Thursday, without reaching the deal he had sought with prosecutors, in a case that has been an embarrassment and a distraction for the US president.

The 54-year-old admitted nine counts related to failing to pay $1.4 million in taxes over the past decade, money that prosecutors said he splurged instead on luxury living, sex workers and a drug habit.

The pleas came on the day jury selection for a trial had been due to start, and hours after Biden had offered to plead guilty in the hope of striking a deal that might keep him out of prison.

But no deal appeared to have materialized and Biden made the pleas in open court, with US District Judge Mark Scarsi cautioning him that he could face a lengthy prison sentence, as well as a fine of up to $1 million.

Scarsi set sentencing for December 16.

A trial had been expected to re-hash sordid details of a life that the defendant and his family -- including the president -- have long acknowledged had gone off the rails.

Biden has already spent a chunk of 2024 in court, having been convicted in Delaware of lying about his drug use when he bought a gun -- a felony.

He has yet to be sentenced for that crime, and could face up to 25 years' detention.

- Political battle -

Lawyers for Biden have said he was only being brought before the court because of who he is.

"They want to slime him because that is the whole purpose," Biden's attorney Mark Geragos reportedly said during an August hearing in which he accused prosecutors of attempted character assassination.

Biden's defense team has argued that the non-payment of taxes was an oversight in a life wrought chaotic by a spiraling drug addiction and the trauma of losing his older brother, Beau, to a brain tumor in 2015.

Biden has paid the back taxes, as well as penalties levied by authorities, and had previously reached a plea deal that would have kept him out of jail.

That agreement fell apart at the last minute, and Biden is understood to have been trying to reach another ever since.

But that has been difficult for prosecutors whose every move in this election year is being scrutinized by Republicans, who charge the defendant is being treated leniently because he is the president's son.

Hunter Biden has for years been a foil for his father's political opponents, who have sought -- without producing evidence -- to smear the family as a group of criminals who have gained wealth and power because of Joe Biden's career.

The elder Biden's withdrawal from the presidential race in favor of Kamala Harris has taken much of the zeal out of the Republican drive to make an example out of his son.

Hunter Biden, a Yale-trained lawyer and lobbyist-turned-artist who lives in Malibu, has said that he has been drug-free since 2019.

hg/st