ROME

Russia announced on Monday it has expelled an Italian diplomat following an "unfriendly" move by Rome to remove two Russian diplomats in March over spying allegations.

According to a statement from the Russian Foreign Ministry, Italy’s Ambassador to Moscow Pasquale Terracciano has been summoned and handed a note saying the naval attache at the Moscow Embassy Curzio Pacifici has been declared “persona non grata.”

The official has been ordered to leave Russia within 24 hours, the statement added.

The move came after Italy expelled two Russian diplomats in March after an Italian navy officer was caught while allegedly handing over classified documents to a Russian official in exchange for money.

The Italian Foreign Ministry on Monday called Russia's decision "unfounded and unjust."

"We consider the decision unfounded and unjust because it is in retaliation to a legitimate measure taken by the Italian authorities in defense of their own security," the ministry said in a statement.

Rome prosecutors have launched an investigation into the case, which involves crimes regarding espionage and state security violations.