Russia said Thursday a new U.S. ballistic missile defense base in northern Poland will lead to an increase in the overall level of nuclear danger, but Warsaw said "threats" from Moscow only strengthened the argument for NATO defenses.

The air defense base, situated in the town of Redzikowo near the Baltic coast, part of a broader NATO missile shield, was opened Nov. 13.

"This is another frankly provocative step in a series of deeply destabilizing actions by the Americans and their allies in the North Atlantic Alliance in the strategic sphere," Russian Foreign Ministry spokesperson Maria Zakharova said.

"This leads to undermining strategic stability, increasing strategic risks and, as a result, to an increase in the overall level of nuclear danger."

Pawel Wronski, Poland's foreign ministry spokesperson, said there were no nuclear missiles at the base, which was purely for defense.

"It is a base that serves the purpose of defense, not attack," Wronski said. "Such threats will certainly serve as an argument to strengthen Poland's and NATO's air defenses, and should also be considered by the United States."

The U.S. base at Redzikowo is part of a broader NATO missile shield, dubbed "Aegis Ashore," which the alliance says can intercept short- to intermediate-range ballistic missiles.

"Given the nature and level of threats posed by such Western military facilities, the missile defense base in Poland has long been added to the list of priority targets for potential destruction, which, if necessary, can be executed with a wide range of advanced weapons," Zakharova said.

The NATO missile shield includes sites in Poland, Romania as well as U.S Navy destroyers at a naval base in Spain and an early warning radar in Turkey, according to NATO.