Russian President Vladimir Putin speaks during a session of the St. Petersburg International Economic Forum (SPIEF) in Saint Petersburg on June 2, 2017. (AFP PHOTO)

MOSCOW, June 14 (Xinhua) -- Russian President Vladimir Putin said Moscow was ready to give an adequate response to NATO's expansion in order to maintain a strategic balance, according to an interview released on Wednesday.

"This is another great strategic mistake made by our partners, because Russia will give an adequate answer to all these actions," Putin said in an interview with U.S. film director Oliver Stone.

He said Russia faced two threats, one of which was the deployment of ballistic anti-missiles in Eastern European countries in the vicinity of Russia's borders.

The other threat was that the launchers of anti-missiles could be transformed into attack systems in a matter of minutes or hours, Putin said.

According to him, these systems were being deployed not only in Eastern Europe, but also aboard ships on duty in the Mediterranean and the northern seas, as well as in Alaska, thus encircling all Russia's territory.

"This will mean nothing else but a new cycle of arms race," Putin said.

Russia will take all necessary steps to respond to NATO's expansion, the president said.

"Our response will be much cheaper, maybe somehow tougher, but it will be effective. And we will preserve this so-called strategic balance. Balance is a very important thing," he said.

The second episode of Oliver Stone's four-episode documentary "The Putin Interviews" was aired on U.S. TV channel Showtime on Tuesday. The final two episodes will be aired later this week.