"There will be a retaliatory response. But overall, of course, this is a very vile and mean provocation by the Czech authorities," Naryshkin told reporters.
On Friday, Czech Prime Minister Andrej Babis announced that two Russian diplomats were declared personae non-gratae in the country.
Rossotrudnichestvo, the Russian foreign cooperation agency, has confirmed that the two expelled diplomats were its employees, and one of them was the acting head of the agency's regional office. The Russian embassy in Prague also called the expulsion a provocation.