Russia has warned it could use nuclear weapons if the North Atlantic Treaty Organization (NATO) tries to cut off Kaliningrad, according to a diplomatic note reported on 30 September 2026.
The note says Moscow is ready to defend its territory with its entire arsenal, nuclear weapons included, if NATO countries try to isolate the region from the rest of Russia. It accuses the alliance of a dangerous and reckless course. It also warns that escalation could bring Russian strikes on decision-making centres in NATO countries from the start of any conflict.
Moscow says in the note that it has information NATO is preparing an air and naval blockade of the exclave. It did not make that evidence public.
Why Kaliningrad matters
Kaliningrad sits on the Baltic Sea between Poland and Lithuania, both NATO members, and is cut off from the Russian mainland. It is a major military outpost. It is home to Russia’s Baltic Fleet and to nuclear-capable Iskander missile systems.
The warning comes more than four and a half years into Russia’s full-scale war in Ukraine, as tension spreads to neighbouring states. Reports have also pointed to alleged Russian airspace incursions in the Baltic region.
NATO response
NATO Secretary General Mark Rutte dismissed the threat at an event hosted by Euronews in Brussels.
“Stop the nuclear threats. This is absolutely not called for and not helpful,” he said.
Rutte also said:
- On the threat: There is no immediate danger to NATO territory, and he does not take the nuclear warning seriously because Russian President Vladimir Putin knows he cannot win a confrontation with the alliance.
- On Moscow’s motive: Russia is trying to distract from its difficulties in Ukraine.
- On the note itself: He declined to confirm its contents, saying it was for Russia to disclose them.
In its formal reply, confirmed by a NATO spokesperson, the alliance said none of its activities or exercises posed a risk to any part of Russia. It also called on Moscow to end its war in Ukraine.
A familiar flashpoint
Kaliningrad has been at the centre of Russian nuclear warnings before. In April 2022, as Finland and Sweden considered joining NATO, former president Dmitry Medvedev said there could be no more talk of a nuclear-free Baltic. Lithuania’s then defence minister, Arvydas Anušauskas, replied that Russia had kept nuclear weapons in Kaliningrad since long before the war in Ukraine.
Both countries have since joined the alliance.
