LOS ANGELES - Hunter Biden pleaded not guilty to nine tax charges in a federal courthouse Thursday, bracing for the possibility he could go on trial twice this year while his father, President Joe Biden, campaigns for reelection.

Federal prosecutors alleged in a 56-page indictment filed last month that the president's son, who moved to Los Angeles in 2018, failed to pay at least $1.4 million in federal taxes from 2016 through 2019. The charges include failing to file and pay taxes, tax evasion and filing false tax returns. Three of the charges are felonies and six are misdemeanors.

The judge, Mark Scarsi, set a tentative trial date of June 20.

The president's son already pleaded not guilty in October to a separate three-count federal indictment in Delaware that alleges he made false statements in 2018 when he completed paperwork to purchase a pistol. That case could also go to trial before the election, provided Hunter Biden does not strike a deal with prosecutors before then.

Republicans, including former President Donald Trump, have seized on Hunter Biden's legal troubles, accusing the Justice Department of not pursuing the case aggressively, and claiming President Biden was involved in his son's finances - something that is not charged in the indictment.

Congressional Republicans are separately investigating Hunter Biden's business activities. On Wednesday, two House committees voted to recommend that the House hold Hunter Biden in contempt of Congress for not submitting to a closed-door deposition. Wednesday's hearings devolved into shouting matches and included Republican members of Congress displaying explicit photos of the president's son on poster boards.

In a dramatic moment of political theater, Hunter Biden made a surprise appearance at one of the hearings to show that he was willing to publicly testify to Congress - just not behind closed doors as Republicans had wanted.

The younger Biden has been public about his struggle with drug addition and has blamed at least some of the alleged behavior in the indictments on a drug-fueled spiral he entered after his brother died of brain cancer in 2015. But prosecutors charge that he failed to pay all the taxes he owed even after he has said he was sober and building a new life in Los Angeles.

Biden's legal team has slammed the charges against him as politically motivated and urged a judge to dismiss the gun charges.

The long-running investigation into the president's son started during the Trump administration and has been heavily criticized by Republicans, who believe it has moved too slowly.

Hunter Biden's two indictments - on the tax and gun charges - almost didn't happen. Over the summer, he reached a tentative agreement with prosecutors to plead guilty to two misdemeanor tax-related charges and admit to the facts of a gun charge.

But that plea deal fell apart after a Delaware judge questioned some of its terms. Soon after, Attorney General Merrick Garland named U.S. Attorney David Weiss of Delaware, who had been leading the investigation, as special counsel - a move that gave him clear authority to file charges outside of Delaware and paved the way for the tax indictment in California. Garland has said that Weiss has complete independence to lead the investigation.

Biden's legal team has said that they believe prosecutors were not legally able charge Biden with crimes because the deal they previously worked out - which enabled him to admit to the facts of the gun case, without actually being charged with unlawful possession of a firearm felony - is actually still in effect. Prosecutors disagree, and the issue will likely have to settled by a judge in the coming months.

In the tax indictment, prosecutors allege that Hunter Biden earned more than $7 million in gross income between 2016 and 2020 from foreign business deals, including payments for his service on the board of the Ukrainian natural gas company Burisma and his work for a Chinese energy conglomerate. He also received another $1.2 million in 2020 and spent the money to fund an "extravagant lifestyle," including drugs, escorts and girlfriends, exotic cars and clothing, the indictment alleges.

The $1.2 million came from a personal friend, according to prosecutors, who routed the money to third parties and then to Hunter Biden, who allegedly spent the funds to rent a "lavish house" in Venice, Calif., and make payments on a Porsche. The indictment charges that he also earned more than $140,000 in payments for his memoir, "Beautiful Things."

Instead of paying his tax bills, however, prosecutors allege that Hunter Biden failed to file taxes on time for a number of years. When he finally filed his tax returns in 2018, the indictment alleges, they included false business deductions that reduced his tax liability.