"As an EU member state, Lithuania's sanctions… are in violation of an array of legally binding international laws that regulate the obligations of Lithuania and the EU as a whole," Kosachev said on social media.
Earlier on Saturday, Governor Anton Alikhanov said the state-owned Lithuanian Railways stopped transit of goods between Russia and its Baltic Sea territory starting at midnight on Friday, citing EU restrictions. Up to 50% of all rail cargo to Kaliningrad has been banned.
"Kaliningrad authorities are discussing transit limits with the Foreign Ministry and the Russian embassy in Lithuania," the governor said on social media.
Three options for response are on the table, including measures that would affect "the Baltic transit complex," Alikhanov said, without elaborating.
"Lithuanian limits on transit to Kaliningrad are illegal and may have far-reaching consequences… If our European neighbors do not lift these illegal restrictions we will recommend that the federal government take response measures," he said.