President Joe Biden's son Hunter pleaded "not guilty" in court Wednesday after a federal judge in Delaware said she was not ready to accept a so-called "sweetheart" plea deal after the prosecution revealed the investigation was ongoing.

Hunter Biden, 53, through his attorneys, had argued the prearranged plea deal should be accepted in its entirety. It included the younger Biden pleading guilty to two misdemeanor tax charges and entering a diversion agreement for a felony gun charge.

Hunter Biden’s plea agreement with the Justice Department appeared to unexpectedly crumble during an initial hearing on the case on Wednesday.

Biden, 53, made his first federal court appearance in Wilmington, Del., where he was set to plead guilty to two misdemeanor counts of willful failure to pay income taxes.

But U.S. District Judge Maryellen Noreika, who is overseeing the case, expressed concern about the terms of the agreement, according to CNN and the Associated Press.

President Joe Biden’s son Hunter pleaded not guilty Wednesday to two tax crimes after a plea deal with federal prosecutors unraveled during a court hearing following the judge’s concerns over the agreement.

Hunter Biden was charged last month with two misdemeanor tax crimes of failure to pay more than $100,000 in taxes from over $1.5 million in income in both 2017 and 2018, and he had made an agreement with prosecutors, who were planning to recommend two years of probation. That deal is now on hold.