Russia's Ambassador to the US, Anatoly Antonov, described NATO as a rudiment of the Cold War in an interview for Newsweek.

Antonov said that the Western alliance's eastward expansion is a violation of the collectively agreed principle of indivisible security in Europe. 

"NATO’s expansion eastwards is against the common and collectively agreed principle of indivisible security in Europe. The transatlantic bloc itself is a rudiment of the Cold War," he said.

This isn't the first time Russia has condemned in harsh terms NATO's recent moves.

On November 15, Kremlin Spokesperson Dmitry Peskov slammed the United States for driving "hysteria" over a possible Russian invasion of Ukraine, after Western countries accused Moscow of amassing troops near the ex-Soviet country. On the same day, US President Vladimir Putin called NATO's drills in the Black Sea - which had also taken place in September - near its border "provocative".

Putin also addressed NATO's eastward expansion on December 23, calling it "unacceptable" in his annual press conference. Answering a British journalist's question about the "possibility of an attack" by Russia on Ukraine, the Russian President said that Moscow does not threaten anyone.

"We are not the ones who are threatening someone. Are we the ones who came there, to the US borders, or to the borders of the United Kingdom or somewhere? They came to us, and now they still say: no, now Ukraine will join NATO as well," he said.

NATO and Russia are scheduled to hold security talks concerning the past months' developments on January 12.