Russia has warned that Lithuania’s decision to stop goods getting from its neighbouring exclave of Kaliningrad to Moscow will have a “serious negative impact on the population”.
The move has seen Lithuania block rail links from Kaliningrad – a Russian territory on its border – via Belarus to Russia.
EU envoy Markus Ederer told officials in Moscow that it has not completely cut off Kaliningrad – as only some goods have been sanctioned and others can be moved by different means.
But Russian Security Council Secretary Nikolai Patrushev warned that “appropriate measures are being worked out” in response to what he described as Lithuania’s “hostile actions”.
Here Sky News looks at the history of Kaliningrad and what the latest sanctions mean for Russian relations with the West.
Where is Kaliningrad?
The Russian city of Kaliningrad is part of the wider Kaliningrad oblast – or region – claimed by the Russians after the Second World War.
Originally known as Konigsberg, Kaliningrad was part of Germany until the Red Army took it from the Nazis in 1945.
After the war in 1946 it was given a new Russian name and its previous German citizens were evicted and replaced with Russians.
It is located between the EU and NATO states of Poland and Lithuania and has a population of around 430,000 people.
It is a key port city on the Baltic Sea and home to Russia’s Baltic Sea Navy fleet.
When the Soviet Union collapsed in 1991, it was allowed to remain part of Russia, while the neighbouring states of Lithuania, Estonia and Latvia became independent.
Professor Michael Clarke, military and defence analyst and former director-general of think tank RUSI, told Sky News: “When the Soviet Union broke up, Kaliningrad was kept separate from Lithuania.
“It was incredibly polluted and Lithuania didn’t want to clean it all up.
“So they were happy to keep it as part of Russia and for rail links to Russia via Belarus to be maintained.
“It seemed like a reasonable compromise at the time – as nobody expected Russia to become so hostile back then.”
But with Vladimir Putin in power, Moscow has become increasingly hostile towards the West – and to NATO in particular.
Relations between Kaliningrad and its neighbours started deteriorating when Mr Putin began modernising the Black Sea fleet around 2006.
They worsened in 2018 when the Russians installed its Iskander missile system there.
“It’s nuclear capable, which doesn’t mean to say there are nuclear weapons there,” Professor Clarke said.
“But there is a belief within NATO that nuclear weapons are being stored there.”
Following the Russian invasion of Ukraine in February, the Baltic states have been among Kyiv’s most vocal supporters – concerned for their own security as the Kremlin tries to increase its sphere of influence.
And this has seen tensions between the Russian exclave and its European neighbours running higher than ever.
What has Lithuania done?
Like other Western powers, the European Union has been gradually expanding its package of sanctions against Russia since it invaded Ukraine in late-February.
In March it banned heavy goods such as coal, metals, timber and electronics destined for Russia.
On Saturday, as an EU member state, Lithuania began to enforce those sanctions, with its state rail operator LTG no longer allowing those goods to move through the country by train – towards Belarus and then to Russia.
With Russian flights also banned, Moscow can only now get goods to and from Kaliningrad by road or sea.
Its governor, Anton Alikhanov, said this will mean only half of imports can get through.
The Kremlin has described the move as “illegal”.
But Viktorija Satrych-Samuoliene, director of strategy for the Council on Geostrategy, says Russia is trying to “push the false narrative” that Lithuania is “blockading” Kaliningrad completely.
She added: “The current attempt of Russia to play a victim in this situation primarily has three aims.
“To further mobilise the Russian population to support the Kremlin’s revisionist and aggressive agenda, to cause unease and doubt in Europe about the agreed sanctions, and to divert attention from the ongoing Russian atrocities in Ukraine.”
Should we be worried – and could the war extend to Lithuania?
The Kremlin has threatened that the latest sanctions will have “serious, negative” implications for the people of Lithuania.
But analysts say this is unlikely to take the form of military intervention – like in Ukraine – as both Kaliningrad’s immediate neighbours are NATO members.
If Vladimir Putin were to invade on either side, it could face retaliation from all 30 NATO states.
Professor Clarke said: “There’s not much the Russians can do about this, unless they want to escalate the crisis to a much greater degree along Kaliningrad’s 40-mile border with Belarus – a strip of land called the Suwalki Gap.
“But I don’t think anyone thinks Russia is going to do that.”
Sky News defence and security editor Deborah Haynes says Moscow could resort to ‘grey zone’ tactics such as cyber-attacks and misinformation campaigns in response.
But according to Professor Clarke, the most likely outcome is Russia using the situation as further ammo against NATO – whose military build-up in the region was the main reason cited for the Ukraine invasion.
“It’s one more thing the Russians will use against NATO,” Professor Clarke says. “It adds to the list of differences between them.”
Asked whether the war could extend to Lithuania, he added: “We said from the beginning that if Russia gets away with this war in Ukraine then the Baltic states will become vulnerable.
“This is a side issue as far as the crisis goes. But all crises are unpredictable – any pressure point like this could escalate.
“We don’t have to panic about it, but we should be keeping an eye on it.”