Russia says it has expanded its list of British citizens barred from entering the country in response to London’s "unconstructive and unfriendly" decision to sanction Russian officials over the poisoning of Kremlin critic Aleksei Navalny.
The Russian Foreign Ministry announced the move on December 30, without mentioning how many British individuals had been blacklisted or their names.
In October, Britain, along with the European Union, imposed travel bans and asset freezes on six senior Russian officials and a state scientific research center for the "attempted assassination" of Navalny, who is currently recovering in Germany from a near fatal poisoning.
Moscow earlier this month hit EU countries with reciprocal sanctions in response to the bloc's measures.
The opposition politician and anti-corruption campaigner fell ill on a flight from Tomsk to Moscow on August 20. He was placed in an induced coma in a Siberian hospital before being transferred to a clinic in Germany.
Laboratory tests conducted in Germany, France, and Sweden have established that Navalny was poisoned with a nerve agent of the Novichok class, a conclusion confirmed by the international Organization for the Prohibition of Chemical Weapons.
Navalny has blamed Russian President Vladimir Putin for his poisoning.
Russian officials, including President Vladimir Putin, have denied involvement and have refused to open a criminal investigation into the incident.
Russia on December 29 also hit German officials with entry bans after the EU and Britain sanctioned Russian intelligence officers over a 2015 hacking attack on the German parliament.