Special counsel David Weiss said the deal his team previously reached with Hunter Biden to resolve a felony gun possession charge was never approved by a probation officer and is not binding.

The Justice Department prosecutors said in a court filing on Tuesday that for the "diversion agreement" to be legally binding, it would have had to be signed by a probation officer after last month's court hearing in Delaware.

They said the official who needed to sign it was Margaret Bray, the chief United States probation officer for the District of Delaware.

"In sum, because Ms. Bray, acting in her capacity as the Chief United States Probation Officer, did not approve the now-withdrawn diversion agreement, it never went into effect and, therefore, none of its terms are binding on either party," prosecutors wrote.

Biden's lawyers on Sunday said they believed an agreement to resolve a felony gun possession charge was "valid and binding."

The filing states that negotiations to amend the plea deal continued after the court hearing on July 26 when a federal judge declined to accept a plea agreement on two tax charges.

Biden's team proposed changes, which prosecutors "did not believe they were in the best interests of the United States" and counter proposed. Biden's team rejected those changes leading to prosecutors informing the judge they had reached an impasse.