The unprofessional behavior demonstrated by the Russian pilot was clearly intentional, according to USA officials.
The incident occurred last Saturday, when Russian radio-surveillance media identified a SU-30 to prevent violation of its borders, explained the same source.
The U.S. P-8A Poseidon did nothing to provoke the maneuver, defense spokesperson Michelle Baldanza told the Daily News.
The Russian fighter jet buzzed the US Navy reconnaissance plane at around 1pm local time (10:00 GMT) as it was flying over the neutral waters of the Black Sea, the ministry said.
U.S. Navy flight pilots are seen aboard the Boeing P-8A Poseidon plane before its departure to take part in the search for the ARA San Juan submarine missing at sea, at a military air base in Bahia Blanca, Argentina, November 26.
In June, the pilot of a USA bomber filmed the nail-biting moment a Russian fighter jet swooped alongside him over the Baltic Sea.
"This interaction was determined to be unsafe", Henderson said in the emailed statement.
As a result of the "provocative" manoeuvre, the U.S. aircraft did "a 15-degree roll" that could have caused "serious harm and injury to all air crews involved", a USA official said.
Martinez said the P-8A was "conducting a routine operation in worldwide airspace" at the time of the intercept.