The Pentagon declined to comment on new information reported by the New York Times, that Teixeira began to post the information in February 2022.
The fleet of Russian "ghost ships" includes both military and civilian ships and reportedly has the goal planning acts of sabotage against the Nordic nations.
A conviction on the Espionage Act charge carries up to 10 years in prison.
A Moscow court next week will hear an appeal by Gershkovich's legal team against a ruling that he be held in pre-trial detention at Moscow's Lefortovo prison until at least May 29.
The 68-year-old convicted spy Jonathan Pollard says he has moved on from his decades in US prison and is now living in Israel.
Russia has presented no evidence to support the case against Gershkovich, which is proceeding in secret.
The Post has indications that the conclusions of the leaked US intelligence that the Mossad aided judicial reform protests is wrong either as disinformation or confusion.