The move practically blocks plans of the city authorities to remove the statues.
The panel made such a decision despite the conclusion drafter previously by the Centre of Cultural Heritage which said that the Green Bridge statues did not need legal protection.
The four groups of statues, representing Soviet soldiers, workers, peasants and students, have stood on the bridge since 1952.
Critics say they are part of Soviet propaganda and an eyesore for people who fought against the Soviet occupation. The other side claims that by keeping the sculptures Lithuania will show it has dealt with ghosts of the past.