Russia has warned that it could deploy more high precision missiles to its Kaliningrad enclave, which borders Poland and Lithuania. Moscow has accused the US of illegally propping up its own forces in the region.

Russia said on Thursday it may send more Iskander missiles to its military base in Kaliningrad as a direct response to the US building up its military presence in neighboring Poland.

The head of the Russian parliament’s defense affairs committee, Retired General Vladimir Shamanov, was quoted by the RIA news agency as saying that Russia was prepared to take retaliatory actions to the US upping the number of its weapons in the region.

Iskander missiles have a range of up to 500 kilometers (310 miles), which could allow Russia to target several NATO member states with pinpoint accuracy. They can also be fitted with a nuclear warhead.

Russia deployed its first set of Iskander missiles in Kaliningrad last year — a move widely interpreted as a response to two US missile interceptor stations hosted in Poland and Romania, which the Kremlin views as a threat on its doorstep.

Russia accuses US of secretly raising troop numbers in Poland

Shamanov also alluded to the US “quietly” deploying an entire armored division in Poland. The US’ Third Squadron and Second Squadron were due to rotate last month while the joint-Russian-Belarusian war games, known as Zapad-2017 (West 2017) were taking place, defense ministry spokesman Igor Konashenkov said – but the Kremlin apparently believes that the exchange was not complete.

“The Second Squadron arrived in Poland quietly with its military equipment. And, during this time, the military equipment of the Third Squadron did not leave Poland and the Baltics,” he said in the statement.

Shamanov said that the US’ conduct in the region was in breach of the main pact that governs Moscow relations with NATO.

NATO dismissed the Kremlin’s accusations, saying that it “fully abides by the NATO-Russia Founding Act.”

“Any accusation that NATO is violating the act or breaking its promises, is untrue,” NATO’s deputy spokesman Piers Cazalet said in a statement, adding that the 4,000 troops deployed in Eastern Europe were “well below any reasonable definition of ‘substantial combat forces’ mentioned in the NATO-Russia Founding Act.”

Eastern Europe engulfed by ‘hysteria’

Last month Russia and Belarus conducted their “Zapad-2017” military drills, which pitted troops against terrorist infiltrators from three “hypothetical” Eastern European countries that control links between Kaliningrad and Belarus. According to Moscow and Minsk, the goal of the Zapad maneuvers is to coordinate actions between regional military commands “in the interest of ensuring military safety.”

Konashenkov said that, thanks to the US, the Baltic region and Poland had been caught up in “hysteria” over a “Russian threat” posed by the war games. “So, who is, in fact, preparing for aggression?” he asked.