US President Joe Biden has issued an official pardon for his son Hunter, who was facing sentencing for two criminal cases.

In a statement, the president said his son had been "singled out", and called his cases "a miscarriage of justice."

"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," he added.

Hunter Biden pleaded guilty to tax charges earlier in September and was found guilty of being an illegal drug user in possession of a gun in June - becoming the first child of a sitting president to be convicted of a crime.

The full and unconditional pardon comes after the president had previously said he would not give his son clemency.

Just a couple of months ago, in September, the White House press secretary said that Biden would not issue a pardon for his son.

But on Sunday evening, President Biden said although he believed in the justice system, "politics has infected this process and it led to a miscarriage of justice".

He added: "once I made this decision this weekend, there was no sense in delaying it further."

"I hope Americans will understand why a father and a President would come to this decision", he said.

In a reaction statement, Hunter Biden said mistakes he made during the darkest days of his addiction had been "exploited to publicly humiliate and shame" his family for political sport.

"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," the 54-year-old added.

The younger Biden has been five and a half years sober, his father said.

In September, Hunter pleaded guilty to nine counts of federal tax fraud, for which he had faced up to 17 years in prison.

He was also convicted of three felonies in connection with a gun purchase in June, for which he had been facing up to 25 years in prison.

Sentencing for these cases had been scheduled for 12 and 16 December.

His legal troubles had been a dark cloud over his father's presidential campaign, which ended in July after Biden pulled out of the election race.

Biden endorsed Vice-President Kamala Harris to succeed him as the Democratic candidate, who lost the election to Republican Donald Trump in November.

Trump is set to take over the Oval Office from Biden on 20 January 2025 - Inauguration Day.