Russia has moved ballistic missiles to and conducted nuclear strike drills from its Kaliningrad exclave, prompting Pentagon fears that Moscow could block access to the Baltic Sea.

There is a “significant amount of capability” in Kaliningrad, including anti-ship weapons, air defenses, and electronic warfare equipment, Lt. Gen. Ben Hodges, commander of U.S. Army Europe, said Wednesday.

“They could make it very difficult for any of us to get up into the Baltic Sea if we needed to in a contingency,” Hodges said in a briefing at the Pentagon.

Russia has conducted what NATO commanders call “snap exercises”: large-scale drills that are not announced and use sophisticated arms. When NATO holds drills of similar size, Russian observers are invited and typically attend. But NATO officials are not invited to Russian’s snap exercises held in Kaliningrad and nearby Belarus.

“We find out about them when they’re happening,” Hodges said.

For exercises in Kaliningrad, Moscow has deployed the mobile, short-range Iskander ballistic missile, Hodges said.

“We have seen them do exercises where … there’s a nuclear strike,” Hodges said. “They don’t [say] gray land, and silver land, or red land, or stuff like that. They say ‘NATO is the adversary’ when they do their exercises. I mean, they’re pretty blunt about that.”

Hodges said Russia has not conducted a full-scale drill to specifically block access to the Baltic Sea. “I haven’t seen one exercise that looked like a complete rehearsal for that,” he said, but “they've done lots of the components that would be required to do those various things in terms of air, maritime, [and] land forces.”

Earlier this year, Russia warned Denmark that Danish ships could become nuclear targets if its government took part in a NATO missile defense project. Hodges called those threats an “irresponsible use of the ‘nuclear’ word.”

“You can understand why our allies on the eastern flank of NATO, particularly in the Baltic region are nervous, are uneasy,” he said.

Tucked between Poland and Lithuania, Kaliningrad is a strategic outpost for the Russian navy. The Russian air force also has a presence there. By blocking access into the Baltic Sea, Russia could prevent NATO forces from reaching its Baltic allies of Estonia, Latvia, and Lithuania.

Since Russia’s invasion of Ukraine nearly two years ago, American forces have spent more time in Eastern Europe training with NATO allies. Those exercises are expected to continue in coming years, Hodges said.