Saying that it was a "red line" for Russia and would lead to a "strong response," Russian President Vladimir Putin issued a strong warning to NATO against deploying its troops and weapons in Ukraine.

Commenting on Western concerns about Russia's alleged intention to invade Ukraine, Putin said Moscow was "also concerned" about NATO exercises near its borders.

Speaking during the Internet Investment Forum, the Russian President said that "NATO's eastward expansion threatens Moscow's basic security interests."

He also expressed concern that NATO "may eventually use Ukrainian territory to deploy missiles capable of reaching Russian command posts, in just five minutes."

He added: "The emergence of such threats is a red mistake for us. I hope that common sense and responsibility will prevail towards their countries and, ultimately, the global community. "

In the same vein, Putin said Moscow has been "forced to face increasing threats," by developing new weapons that exceed the speed of sound.

He went on: "What should we do? We'll need to develop something similar to targeting those who threaten us. And we can do that now. "

He noted that a new supersonic missile, scheduled to enter service with the Russian Navy early next year, would "also take only five minutes to reach those issuing orders."

The Zircon missile, which has a speed of over 9 times higher than the speed of sound, has undergone a series of tests, most recently on Monday.