Over the weekend, Bulgarian Prime Minister Boyko Borissov said that his country is ready to declare Russian diplomats personae non-gratae.
"If Bulgaria takes unfriendly steps towards Russia, then naturally they should understand that there will be reciprocal steps from our side," Grushko told reporters.
Earlier in March, the Bulgarian Prosecutor's Office said it brought espionage charges against six citizens, including servicemen and public servants, who allegedly transferred classified data to Russia.
Meanwhile, NATO Secretary-General Jens Stoltenberg said on Monday that the organisation is closely following an investigation into the alleged "Russian spy ring" in Bulgaria.
"We are, of course, following closely the Bulgarian investigation into the alleged Russian spy ring. NATO is always very focused on the protection of classified documents and classified information and we fully support the work of our ally Bulgaria to tackle Russia's malign activities on its territory," Stoltenberg said at a press conference ahead of the upcoming NATO foreign ministers’ meeting.
Earlier in March, the Bulgarian Prosecutor's Office said it brought espionage charges against six citizens, including servicemen and public servants, who allegedly transferred classified data to Russia. Over the weekend, Bulgarian Prime Minister Boyko Borissov said that his country is ready to declare Russian diplomats personae non-gratae. Russian officials have said that Moscow was ready to respond in kind to any potential hostile moves taken by Sofia.