News media reports said the incident occurred in international waters east of the Korean peninsula, Reuters wrote.
A U.S. Navy official said two Russian TU-142 "Bear" aircraft flew within a nautical mile of the Reagan, prompting it to launch four F-18 fighter jets to escort the planes away from the ship.
The TU-145 Bear is a long-range anti-submarine warfare plane and a variant of the TU-95 Bear strategic bomber.
The Navy official, speaking on condition of anonymity, said the pilots from both sides behaved professionally and the TU-145s moved away from the U.S. carrier.
Media accounts quoted Navy officials as saying the incident was not unprecedented.