US President Joe Biden has pardoned his son, Hunter, a reversal after pledging to stay out of legal proceedings against the younger Biden who pleaded guilty to tax violations and was convicted on firearms-related charges.

“Today, I signed a pardon for my son Hunter. From the day I took office, I said I would not interfere with the Justice Department’s decision-making, and I kept my word even as I have watched my son being selectively, and unfairly, prosecuted,” Biden said in a statement released by the White House late on Sunday (US time).

“I hope Americans will understand why a father and a president would come to this decision.”

The White House had said repeatedly that Biden would not pardon or commute the sentences of his son, a recovering drug addict who became a target of Republicans, including US president-elect Donald Trump.

“No reasonable person who looks at the facts of Hunter’s cases can reach any other conclusion than Hunter was singled out only because he is my son,” Biden said in a statement released on Sunday (US time) before leaving for a trip to Africa.

The grant of clemency said Biden had granted “a full and unconditional” pardon to Hunter Biden for any offences in a window from January 1, 2014, to December 1, 2024.

Hunter Biden faced sentencing for the false statements and gun convictions in November.

In September he pleaded guilty to federal charges of failing to pay $US1.4 million ($A2.2 million) in taxes while spending lavishly on drugs, sex workers and luxury items.

He was scheduled for sentencing in that case on December 16.

“I have admitted and taken responsibility for my mistakes during the darkest days of my addiction – mistakes that have been exploited to publicly humiliate and shame me and my family for political sport,” Hunter Biden said in a statement on Sunday, adding he had remained sober for more than five years.

“In the throes of addiction, I squandered many opportunities and advantages … I will never take the clemency I have been given today for granted and will devote the life I have rebuilt to helping those who are still sick and suffering.”

Republicans, led by Trump, criticised Biden’s move. He said on his Truth Social platform it was a “miscarriage of justice” while others remained in prison for their parts in the violent attack on the US Capitol on January 6, 2021.

“Does the Pardon given by Joe to Hunter include the J-6 Hostages, who have now been imprisoned for years? Such an abuse and miscarriage of Justice!” Trump wrote.

“Joe Biden has lied from start to finish about his family’s corrupt influence-peddling activities,” said Representative James Comer, chair of the House committee on oversight and accountability.

The President, whose son Beau died of brain cancer in 2015, said his opponents had sought to break Hunter with selective prosecution.

He said people were almost never brought to trial for felony charges for how they filled out a gun form, and said others who were late in paying taxes because of addiction but paid them back with interest and penalties, as his son had, typically received non-criminal resolutions to their cases.

“It is clear that Hunter was treated differently. The charges in his cases came about only after several of my political opponents in Congress instigated them to attack me and oppose my election,” Biden said.

“In trying to break Hunter, they’ve tried to break me – and there’s no reason to believe it will stop here. Enough is enough.”

In August 2023, lawyers for Hunter Biden said prosecutors had reneged on a plea deal that would have resolved the tax and firearms charges.

The President said the plea deal “would have been a fair, reasonable resolution of Hunter’s cases”.

Biden said he had made his decision to pardon at the weekend.

The President, his wife, Jill Biden, and their family including Hunter, spent the Thanksgiving holiday in Nantucket, Massachusetts, and returned to Washington late on Saturday.

“Here’s the truth: I believe in the justice system, but as I have wrestled with this, I also believe raw politics has infected this process and it led to a miscarriage of justice – and once I made this decision this weekend, there was no sense in delaying it further,” Biden said.

“I hope Americans will understand why a father and a president would come to this decision.”

-with AAP