"Missile deployment does not help to lower tensions or restore predictability to our relations," the source said. "NATO called for more transparency on military activities to avoid incidents and the risk of misunderstandings."
Earlier in the day, Russian presidential spokesman Dmitry Peskov told reporters that Moscow has the right to safeguard its borders in view of NATO’s buildup close to Russia’s borders.
"Russia is doing its utmost to ensure its security amid NATO’s expansion towards its borders. The alliance is indeed an aggressive bloc, so Russia is doing everything it can in that regard. In this case it has all sovereign rights to take all necessary steps on its territory," Peskov said.
During its summit in Warsaw in July 2016 NATO made a decision to deploy four multinational battalions to the Baltic States and Poland as of January 2017, creating armament depots and deploying heavy military equipment there. In addition to that, the US announced its intention to send a 6,000-strong brigade to Poland in 2017.