Russia expelled 23 British diplomats on Saturday in a carefully calibrated retaliatory move against London, which has accused the Kremlin of orchestrating a nerve toxin attack on a former Russian double agent and his daughter in southern England.
The British Foreign Office insisted that "Russia's response doesn't change the facts of the matter" and that "the onus remains on the Russian state to account for their actions".
"This crisis has arisen as a result of an appalling attack in the United Kingdom, the attempted murder of two people, using a chemical weapon developed in Russia and not declared by Russia at the Organization for the Prohibition of Chemical Weapons, as Russia was and is obliged to do under the Chemical Weapons Convention", he added.
He was told 23 British diplomats must leave Moscow within a week.
The 29-member North Atlantic Treaty Organisation alliance expresses solidarity with Britain over what it calls the first offensive use of a nerve agent on the military alliance's territory since World War II.More news: UK Using Nerve Agent Row to Distract from Brexit: Moscow
Britain's ambassador to Russia, Laurie Bristow, was summoned to Russia's foreign ministry on Saturday and was handed Russia's response to the UK's sanctions.
"It's a great shame for the Russian people that they're closing the British Council which has done an bad lot to educate Russian people in the English language and to help them get jobs and opportunities around the world", he told the BBC.
Russia's Investigative Committee is opening a criminal investigation into the attack and said it was ready to cooperate with Britain.
Skripal had taken his daughter, who was on a visit from Moscow, out for lunch in Salisbury before they both collapsed on a bench.
"We will always do what is necessary to defend ourselves, our allies and our values against an attack of this sort, which is an attack not only on the United Kingdom, but upon the global rules-based system on which all countries, including Russian Federation, depend for their safety and security", Bristow told reporters after being informed of the expulsions.More news: Violent protests erupt in Madrid over migrant vendor's death
Russia's ambassador to the UK, Alexander Yakovenko, said Britains response has been a "gross provocation" against Russian Federation and the ensuing investigation is "absolutely un-transparent and it's secret".
That will be seen by Britain as a low blow, hurting the Russian people - not the British government.
It also says it has begun a separate probe into the suspected murder of a Russian living in London, Nikolai Glushkov. British police said on Friday that he died from compression to the neck and opened a murder investigation.More news: Rivers slams officials after Clippers' loss to Rockets
- Parkland Surveillance Video Shows Deputy Did Not Confront Mass Shooter
- PM Modi to scientists: Can you develop more efficient solar modules?
- A day of smartphone silence
- Russia Calls British PM's Allegations Over Poisoning 'Insane'
- In Manchester, Flake Says Trump is Waging a 'War on Objective Reality'
- Russia Orders the Expulsion of 23 British Diplomats in Retaliation
- All England Championship 2018: PV Sindhu entered into the semi-final
- Neymar criticised for 'self-centred' wheelchair tribute to Stephen Hawking
- Are Analysts Bearish Hunting plc (LON:HTG) After Last Week?
- Israel Condemns Poisoning of Russian Spy, Without Mentioning Russia