A US federal court has held the first hearing in a case involving Hunter Biden, the second son of US President Joe Biden.

The criminal prosecution of Hunter, who is accused of lying about his drug use to buy a gun, is the first for a sitting US president's child.

On Monday, Hunter appeared at the federal courthouse in the eastern US state of Delaware.

He has pleaded not guilty to the charges, including lying that he was not using illegal drugs to acquire a handgun in 2018.

During the hearing, the jury was selected.

Prosecutors plan to call witnesses, including Hunter's ex-wife, to prove that he had been addicted to illegal drugs.

President Biden said in a statement, "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..."

Last week, a jury in New York found former US President Donald Trump guilty in a hush money case involving an adult film star.

It is unclear how Hunter's trial and the guilty verdict against Trump could influence the presidential election in the fall.