Russia supplies Finland with small quantities of gas and oil, but Finland was already preparing to sever those supplies in keeping with European Union decisions to reduce dependency on Russian energy. One possible early response came Saturday with an announcement by the Russian state-owned company RAO Nordic that it has halted electricity exports to Finland, although it was unclear whether the move was intended as a punishment. Russia blamed Western sanctions for the move, saying they had made it difficult for Russia to receive payments for the supplies.

Finland shrugged off the action. Finnish officials said they had already been scaling back imports of Russian electricity to guard against possible attacks on the country’s infrastructure, and Russian electricity accounted for only 10 percent of its consumption.

Russia may try to launch cyberattacks against Finnish infrastructure or wage hybrid warfare in an attempt to sway Finnish public opinion, but Finland has highly developed systems capable of countering any such efforts, said retired Maj. Gen. Pekka Toveri, a former chief of Finnish military intelligence.