The statement says Switzerland's charge d'affaires in Russia was summoned today to the Foreign Ministry and told that Moscow considers the decision to extradite Adamov to the United States a "disappointing" move.
Switzerland on 3 October cleared the way for Adamov's extradition to the United States, where he is expected to face trial.
U.S. investigators allege that Adamov embezzled $9 million meant to improve Russia's nuclear safety while he was in office.
Russian authorities have unsuccessfully tried to convince Switzerland to extradite Adamov to Moscow.
Adamov's Secrets, Nuclear And Otherwise