The military bloc's aviation has significantly intensified its training flights near Russia's border to imitate missile strikes on the country, Russian Defence Minister Sergei Shoigu told Rossiya 24 in an interview.
As an example, Shoigu cited the recent sighting of American B-52 strategic bombers near the border for the first time in long.
"We understand what this activity is about, where it is stemming from", the minister stressed.
He added that everyone has already come to terms with the fact that there is one "master" in a unipolar world, and when another "pole" appears, the "master" doesn't like it very much.
"Russia has no other choice - it has to be strong, and now everything is being done so that nothing threatens the country", he concluded.
For several weeks now, the Russian Defence Ministry has been reporting NATO aircraft approaching Russia's borders in the airspace over the Black and Baltic Seas. Reconnaissance aircraft and bombers have subsequently been intercepted by Russian Su-27 fighter jets.
On Friday, three B-52H bombers of the US Air Force approached the Russian border over the Black Sea, while eight Russian fighter Su-27 and Su-30 were scrambled to intercept them.