Russia is expelling the Bulgarian military attache’s aide Lieutenant-Colonel Mitko Borisov in retaliation for the expulsion of a Russian diplomat from Sofia. A note to this effect was handed to Bulgaria’s ambassador in Moscow Atanas Krastin, who was summoned to the Russian Foreign Ministry on Monday.

"On December 28, Bulgaria’s ambassador Atanas Krastin was invited to the Russian Foreign Ministry where he was handed the ministry’s note declaring an aide to the military attache of the Bulgarian embassy in Moscow, Lieutenant-Colonel Mitko Borisov, as persona non-grata. The aforesaid embassy staffer was ordered to leave Russia within 72 hours," the Russian Foreign Ministry said.

The measure is in retaliation to Bulgaria’s decision to expel the military, air and naval attache at Russia’s embassy in Sofia on December 19.

He was the sixth Russian diplomat to have been expelled from Bulgaria over the past two years. There were allegations that he had been involved in intelligence activities in the country starting from 2017, in particular, gathering information about US military personnel’s participation in exercises in Bulgaria. He was ordered to leave Bulgaria within a 72-hour deadline. The Russian embassy stressed that no proof of any activities incompatible with the diplomatic status had been presented. Russia stressed its right to take retaliatory steps.