"Western media's allegations of a 'dangerous' fly-by of a Russian Su-27 jet and an American RC-135 in the Baltics are false," the spokesman assured.
Igor Konashenkov also said that Su-27's flight was conducted in accordance with international safety standards.
On Thursday, Russia's military detected an unknown aerial target that was heading for the Russian border on a high speed, he noted.
"To identify the target, one of the Su-27s of the Baltic Fleet aviation forces on duty was sent. It has performed its [the target's] flyby and identified the object as a reconnaissance plane RC-135U of the US Air Force," Konashenkov explained.
After the visual contact with the Russian Su-27, the US reconnaissance plane changed its course to the opposite, the spokesman added.
Earlier on April 11 and 12, the USS Donald Cook guided missile destroyer experienced several 'close interactions' with Russian Su-24 bomber jets on the Baltic Sea, with Pentagon officials calling the jets maneuvers 'aggressive', 'unsafe and unprofessional'.
The US considers the incident so serious that Secretary of State John Kerry vowed to raise the issue with Russian Foreign Minister Sergei Lavrov.