Moscow ( CNN ) -- Russia said Wednesday that it blamed `` unfriendly '' actions by Britain for a recent diplomatic spat that led both nations to expel each others ' diplomats . `` The British side has recently took an unfriendly step , groundlessly declaring persona non grata a diplomat at the Russian Embassy in London . We were compelled to take a similar step in response , '' a statement on the Russian Foreign Ministry said . `` It is regretful that the actions of the British side were undertaken at a moment when our relations with Britain have just started to improve . The initiators of this incident bear full responsibility for its consequences . '' The statement comes after the United Kingdom expelled a Russian diplomat on suspicion of spying , and Russia kicked out a British embassy staffer in Moscow in retaliation . Britain asked the Russian to leave on December 10 `` in response to clear evidence of activities by the Russian intelligence services against U.K. interests , '' British Foreign Secretary William Hague said Tuesday . Russia told the British diplomat to leave Moscow on December 16 , Hague said . Hague said there was not `` any basis '' for the expulsion . CNN 's Maxim Tkachenko contributed to this report .
Russia expels a British diplomat on suspicion of spying . London expels a Russian embassy staffer in response . London says the Russian embassy staffer was working `` against Russia interests ''