MOSCOW (Reuters) - Russia has deployed advanced nuclear-capable Iskander missiles to its Kaliningrad exclave on the Baltic Sea, the RIA news agency quoted a senior lawmaker as saying on Monday.

Russia has said previous deployments of Iskander missiles to Kaliningrad, a slice of Russia wedged between Poland and Lithuania, were temporary and a response to the United States building up its forces in the Baltic region.

Washington says placing such missile systems near the Baltic states and NATO member Poland is “destabilizing,” while U.S. officials have expressed concern that the deployments represent a permanent upgrade to Russia’s forces in the area.

Vladimir Shamanov, head of the Russian lower house of parliament’s defense committee, said on Monday that Iskander missile systems had been sent to Kaliningrad, but did not say how many or for how long, RIA reported.

“Yes, they have been deployed,” it quoted him as saying. “The deployment of foreign military infrastructure automatically falls onto the priority list for targeting.”

The Iskander, a mobile ballistic missile system codenamed SS-26 Stone by NATO, replaced the Soviet Scud missile. Its two guided missiles have a range of up to 500 kilometers (about 300 miles) and can carry either conventional or nuclear warheads