"Our missile defenses are defenses, they threaten no one, and for the Russians then to use that as an excuse to have a military build-up in this part of the world which is at peace is really an example what might be even viewed as paranoia on the part of Vladimir Putin," McCain told journalists.
"They must understand that these are defensive systems and defensive systems alone. And by the way, those missile defense systems played a very important role in ending the Cold War," the senator and a 2008 presidential candidate said.
McCain is attending a conference organized by the Parliamentary Forum for Democracy on the democratic situation in Eastern Europe.
Read Senator McCain's address in Vilnius University on Wednesday
On the eve of the conference, the chairman of the Committees on Foreign Affairs of the Lithuanian and Polish parliaments issued a joint statement rejecting Russia's arguments regarding strengthening of military forces in Kaliningrad region in response to NATO's anti-missile defense system. Chairman of the Lithuanian parliamentary Committee on Foreign Affairs, Emanuelis Zingeris, gave a copy of the statement to McCain on Thursday.
Russia's military and political leadership have said the country would deploy the most modern surface-to-surface and surface-too-air missiles, like S-400 and Iskander, if NATO failed to take into account Russia's position regarding the missile defense system. According to Russian media reports, S-400 missiles were deployed in Kaliningrad in April.