Jurors have heard unsparing accounts of Hunter Biden's drug use in his own words as his trial on gun charges, the first-ever prosecution of a child of a sitting US president, has gotten under way.

Hunter Biden, 54, the only surviving son of President Joe Biden, is charged with lying about his illegal drug use when buying a handgun in 2018, a felony.

He is also charged with illegal possession of the firearm.

"No one is above the law — it doesn't matter who you are and what your name is," prosecutor Derek Hines said in his opening statement at the federal trial being held in the Biden family stronghold of Wilmington.

"Robert H. Biden chose to illegally own a firearm" when "he was a user of crack and a drug addict," Hines added, as the court was shown an image of the Colt Cobra revolver at the heart of the case.

'I cooked and smoked'

The prosecutor played extracts from Hunter Biden's memoir "Beautiful Things" recorded by Biden himself, in which he recalled his descent into addiction when he would desperately seek out crack cocaine.

"I cooked (crack) and smoked. I cooked and smoked," said the extract played to the court, taken from his audiobook.

First Lady Jill Biden was in court again on Tuesday and had a serious expression as the extracts were played.

Hunter Biden's lawyer said that he "was not using drugs when he bought that gun" and that it "was never loaded, never carried, never used" during the 11 days he owned it.

Biden, a Yale-trained lawyer and lobbyist-turned-artist, has stated that he has been sober since 2019.

An FBI agent took the stand after both sides gave their opening statements.

A 12-member jury with four alternates was seated on Monday.

Expected to last up to two weeks, Hunter Biden's trial comes as his father is seeking reelection, and just days after the conviction on business fraud charges of Donald Trump, the president's likely opponent in November.

The proceedings, along with another trial in which Hunter Biden faces tax evasion charges in California, complicate Democrats' efforts to keep the focus on Trump, the first former president ever to be convicted of a crime.

Trump also faces three far more serious criminal cases, including for his alleged efforts to overturn the results of the 2020 presidential election.

The president did not attend but said he and Jill were "proud" of Hunter Biden.

"As the president, I don't and won't comment on pending federal cases, but as a dad, I have boundless love for my son, confidence in him, and respect for his strength," Biden said in a statement.

Addiction

If found guilty, Hunter Biden could face 25 years in prison, although as a first-time offender, jail time is unlikely.

The president's son has long been the target of hard-right Republicans. No charges have ever been brought.

His business dealings in China and Ukraine have also formed the basis for attempts by Republican lawmakers to initiate impeachment proceedings against his father.

Those efforts too have gone nowhere.

The White House said last year that there would be no presidential pardon for Hunter Biden in case of a conviction.