Russia has expelled 23 British diplomats in a retaliatory move in the spy poisoning stand-off.
Russia's Foreign Ministry had today summoned the British ambassador for talks in the dispute over a nerve agent attack on a former spy in the UK.
A Russian Ministry of Foreign Affairs statement said: "On March 17, Ambassador of Great Britain to Russia Laurie Bristow was summoned to the Foreign Ministry, where he was handed a note stating that in response to the provocative actions of the British side and groundless accusations against the Russian Federation with regard to the incident in Salisbury, UK on March 4, 2018, the Russian side has taken the following decisions in response.
"Twenty-three diplomatic staff of the UK Embassy in Moscow are declared persona non grata and are to be expelled from Russia within a week.
"Taking into account the disparity in the number of the two countries' consular missions, the Russian Federation recalls its agreement on the opening and operation of the Consulate General of the United Kingdom in St Petersburg.
"Respective procedures will be followed in accordance with international legal practice.
"Due to the unregulated status of the British Council in the Russian Federation, its activities are terminated.
"The British side is warned that in case of further unfriendly actions against Russia, the Russian side reserves the right to take further retaliatory measures."
Speaking in Moscow, British Ambassador Laurie Bristow said: "Russia today has informed me of steps that Russia will be taking."
The ambassador did not reveal what steps Moscow had taken.
He said the UK would "always do what is necessary to defend ourselves, our allies and our values against an attack of this sort".
British Prime Minister Theresa May earlier ordered 23 Russian diplomats expelled as part of measures to punish Russia over the March 4 poisoning of former spy Sergei Skripal and his daughter Yulia in the city of Salisbury.
Speaking at the Conservative Spring Forum, Theresa May said: "Today our ambassador in Moscow was informed by the Russian government of the action they are taking in response.
"In light of their previous behaviour we anticipated a response of this kind and we will consider our next steps in the coming days alongside our allies and partners.
"But Russia's response doesn't change the facts of the matter - the attempted assassination of two people on British soil for which there is no alternative conclusion other than that the Russian state was culpable.
"It is Russia that is in flagrant breach of international law and Chemical Weapons Convention.
"I repeat today that we have no disagreement with the Russian people. Many Russians have made this country their home and those who abide our laws and make a contribution to our society will always be welcome.
"But we will never tolerate a threat to the life of British citizens and others on British soil from the Russian government."
Mrs May continued: "We can be reassured by the strong support we have received from our friends and allies around the world.
"From the United States, Nato and the European Union. From our UN and Commonwealth partners. I'm grateful too for the strong support I've received from the first ministers of Scotland and Wales.
"And in the House of Commons this week we saw a consensus as member after member across all parties stood up to condemn Russia's actions and to support the position of Her Majesty's Government.
"Because this act of Russian aggression is the very antithesis of the liberal and democratic values that define the United Kingdom - the rule of law, freedom of speech, the toleration of dissenting and minority views, a free press, fair and democratic elections, a thriving civil society.
"These are the foundation stones of human freedom. They don't come about by accident and they're certainly not the default setting for any society.
"They take years of patient work to build up, they face constant threats and they must always be defined. They are the values which unite us as a country."
British Foreign Secretary Boris Johnson has accused Russian President Vladimir Putin of personally ordering the poisoning.
Mr Putin's spokesman denounced the claim.