Brussels: Russia has warned NATO that it could use its entire military arsenal, including nuclear weapons, if the Western alliance attempts to isolate the Russian exclave of Kaliningrad from the rest of Russia.

The warning was delivered in a diplomatic document sent to NATO as tensions continue to rise around the Baltic Sea. Moscow accused the alliance of following what it described as a dangerous course that could increase the risk of a direct military confrontation.

Russian officials said any attempt by NATO countries to cut off Kaliningrad would be considered a threat to Russian territory. Moscow also warned that a wider conflict could involve attacks against decision-making centres in NATO member states.

Kaliningrad is strategically important to Russia because it is located between Poland and Lithuania, both members of NATO. The heavily militarised territory hosts Russian military facilities and forms an important part of Moscow’s military presence in the Baltic region.

Russia’s warning followed statements from Russian diplomatic missions in several European countries alleging that NATO was preparing scenarios involving an air and naval blockade of Kaliningrad. Moscow has presented such a development as a potential threat to its territorial integrity.

NATO has rejected the suggestion that its activities are aimed at isolating Kaliningrad. NATO Secretary General Mark Rutte said the alliance is defensive and called on Russia to stop making nuclear threats. He also indicated that the alliance does not currently see an imminent threat to NATO territory from Russia.

The exchange comes against a backdrop of increased military activity in the Baltic Sea. NATO members have conducted exercises in the region and have strengthened efforts to protect critical infrastructure, including undersea communication cables and energy networks.

European governments have also raised concerns about alleged Russian hybrid activities, including suspected sabotage and other forms of disruption. Moscow has rejected accusations that it is conducting a campaign designed to destabilise European countries.

The Kaliningrad issue has become particularly sensitive because of the territory’s geographic position. Unlike most of Russia, Kaliningrad does not share a land border with the Russian mainland. It is separated from the rest of the country by other states and the Baltic Sea.

For NATO, any attempt to blockade the territory would carry major military and political implications. For Russia, maintaining access to Kaliningrad is considered an important strategic interest.

Despite the sharp diplomatic language, NATO officials have indicated that there is no immediate military confrontation over Kaliningrad. The latest statements nevertheless demonstrate how quickly tensions in the Baltic region can escalate through military exercises, political warnings and competing security assessments.

The situation is being closely monitored by European governments as NATO continues strengthening its eastern defences while Russia maintains its military presence around the Baltic region.