Poland and the Baltic states of Estonia, Lithuania and Latvia on Monday expressed alarm at reports that Russia planned to deploy, or already has deployed, Iskander-M missiles close to their borders.
The Estonian and Lilthuanian defense ministers both called the news "alarming," describing it as "cause for concern."
Latvian Defense Minister Artis Pabriks said on Monday that such a move would change the "balance of powers in our region" and "threatens several Baltic cities." The United States also expressed its concern, with State Department deputy spokeswoman Marie Harf saying "we've urged Russia to take no steps to destabilize the region."
Washington said it had received no official word from Moscow about the deployment.
On Saturday, the German mass-circulation Bild newspaper reported that secret satellite imagery showed Iskander-M missiles stationed near the Polish border.
This was followed by a report in the pro-Kremlin newspaper Izvestia on Monday saying that Moscow had deployed Iskander missiles with a range of hundreds of kilometers in its territory of Kaliningrad, which is located between Poland and Lithuania, both NATO member states. According to the unnamed Defense Ministry official quoted as a source, the missiles have been there "for some time."
Russia said in 2011 it might put Iskanders in Kaliningrad as part of a response to an anti-missile shield the US is building in Europe with help from NATO nations. There have been media reports since of plans to deploy the missiles, but no confirmation it had happened.
The advanced version of the Iskander missile has a range of 500 kilometers (310 miles). It is nuclear-capable, and could also potentially be used to destroy ground-based radar and interceptors of the new NATO shield. Washington and NATO have long argued that the missile shield is not aimed at Moscow, but is intended to protect the West from potential threats from so-called "rogue states."