Gates has been negotiating the plea deal for a month and already spoken to the team of Counsel Robert Mueller, sources familiar with the case told the CNN.
The media outlet suggested that the agreement could be announced in the coming days and might be used by the former FBI director to build a case against the president or his officials.
Both men pleaded not guilty to 12 counts, including for failing to register under the Foreign Agents Registration Act of 1938 for their work for the Ukrainian government. Gates was freed from house arrest in mid-January.
Two separate investigations into alleged Russian meddling in the US election, which have been dubbed a "witch hunt" by Trump, are currently being conducted by the US Congress and by FBI Special Prosecutor Robert Mueller. Mueller has charged four people involved with or related to Trump's campaign with a variety of crimes, but none of the cases unveiled nefarious US-Russian plots to keep Trump's 2016 opponent, Hillary Clinton, out of the White House. The Kremlin has refuted claims of Russian interference as "groundless."