Moscow’s defense ministry announced the incident saying one of its SU-27 jets was dispatched to an area over the Baltic Sea.
The defense ministry said an aircraft was detected flying along the border, prompting the intercept.
News report from Russia claims the SU-27 was sent out shortly after 7am GMT – or 3am on the east coast of the US.
The ministry then went on to claim the Russian jet identified the plane as a US B-52 strategic bomber and escorted it until it flew further away from the border.
US European Command spokesman Captain Joe Alonso told reporters the alleged incident was being investigated.
He could not confirm whether or not it took place.
Similar incidents have happened close to Russian airspace in the past. In September, a Russian fighter jet flew within 10 feet of a Navy surveillance aircraft.
At the time, American officials called it an unsafe intercept over the Black Sea.