The Russian government has responded with anger and fury after the small Baltic country of Lithuania, a member of the European Union and NATO, cut Moscow off from its enclave of Kaliningrad.

In a sternly worded statement, Moscow accused Lithuania of launching an "unprecedented" and "illegal" act, with the Foreign Ministry saying that the restriction was "openly hostile" and suggested Moscow would "take actions to protect its national interests."

What those actions would be, specifically, the Russians did not specify, but the rhetoric nevertheless renewed fears of a wider conflict that could ignite World War III since Lithuania is a member of NATO and part of being in the alliance means all nations come to the aid of a member state under attack.

According to Radio Free Europe, "Lithuanian officials imposed the restrictions beginning on June 20 in an effort to shore up punitive measures that followed Russia's ongoing invasion of Ukraine on February 24."

"The decision is indeed unprecedented. It violates every possible rule," Russian President Vladimir Putin's spokesman, Dmitry Peskov, said.

"We understand that it stems from the European Union's decision to expand sanctions to the transit of goods. We believe that it is illegal, too," Peskov added.

That said, Lithuanian officials countered by insisting Russia could ship goods to its enclave by sea, as it is Russia's only ice-free port year-round.

The Russian Foreign Ministry said this week that officials summoned the Lithuanian ambassador in Moscow to protest what it called "provocative" and "openly hostile" measures.