Moscow will take steps to respond if NATO begins regular troop rotations in the Baltics, Russia's permanent mission to NATO said on Wednesday.
The warnings come after NATO Secretary General Anders Fogh Rasmussen told The Guardian newspaper it was likely there would be regular troops rotations in the Baltics.
Baltic officials have called for a permanent NATO presence in the region amid the crisis in the Ukraine and what they see as a threat from Russia.
But Russia's Foreign Ministry say the NATO military drills would harm security in the region.
"More visible NATO military presence in the east will be detrimental to the Euro-Atlantic stability. Russia will react to NATO moves eastwards with a view to ensure its security," the foreign ministry wrote on its twitter account.
"NATO is willing to satisfy its eastern allies in their phobias. What about fighting real challenges to international security?" another "tweet" indicates.
"One should not be misled by the term "rotation". What matters is permanence of NATO presence in the East," the ministry also said.
A major NATO summit in Wales next week will discuss the deployment of allied armed forces in military bases in east Europe, Rasmussen told "The Guardian" on Tuesday.
The Cardiff summit is likely to come up with a solution for calls to a permanent NATO presence, alliance sources said, which would avoid the term "permanent" for the new bases. But the impact will be to have constantly manned NATO facilities east of what used to be the iron curtain.
Rasmussen said that the bases could be established on a rotation basis.
"The point is that any potential aggressor should know that if they were to even think of an attack against a NATO ally they will meet not only soldiers from that specific country but they will meet NATO troops. This is what is important," said Rasmussen.
When asked whether there would be permanent international deployments under a NATO flag in east Europe, Rasmussen said: "The brief answer is yes. To prevent misunderstanding I use the phrase "for as long as necessary". Our eastern allies will be satisfied when they see what is actually in the readiness action plan."