We are talking about energy and transport infrastructure - facilities where damage can disrupt the functioning of the entire energy system, said Lithuanian President Gitanas Nauseda at a joint press conference in Vilnius with his Latvian counterpart, Edgars Rinkevics.
They are referring to intelligence reports.
The planning takes place at the highest level, practically in Moscow, Nauseda said.
According to Rinkevics, Russia's purpose is to test how NATO and the EU would act in a critical situation.
The warning is the latest in a series of Russian threats to NATO's eastern flank and should be seen in the context of Western support for Ukraine. Polish Prime Minister Donald Tusk said in June that "various forms of escalation" were to be expected from Russia.
