It is therefore entirely reasonable that Britain asked Russian Federation to clarify if it was behind the attack or had somehow lost control over the nerve agent, two possible explanations for the Salisbury incident.
And it said it had halted the activities of the British Council, Britain's global organisation for cultural relations and educational opportunities.
Other moves by the United Kingdom in response to the poisoning include legislative powers to defend against hostile state activity and the suspension of high-level contacts between the U.S. and the Russian Federation.
On Saturday, the Russian foreign ministry tweeted an RT interview with Alexander Shulgin, Russia's permanent representative to the Organisation for the Prohibition of Chemical Weapons (OPCW), in which he suggested British authorities were "afraid". "We have never encountered this level of discussion on the global stage", Putin spokesman Dmitry Peskov told reporters, saying he's been surprised by the British reaction. They remain in a critical condition. Russia has demanded consular access to Yulia Skripal, a Russian citizen, and complained that Britain has not responded to that request.
On March 15 Britain, France, Germany and the United States say in a rare joint declaration that "there is no plausible alternative explanation" to Russian involvement and call on Moscow to provide "full and complete disclosure" of the Soviet-era chemical programme that developed Novichok.
Russian Federation could announce measures against Britain "any minute"
Britain says the Russian state is behind the poisoning of ex-spy Sergei Skripal and his daughter in the English city of Salisbury. Britain this week ordered the expulsion of 23 Russian diplomats and cancelled high-level bilateral contact with the Kremlin.
Federer seeking 6th title at Indian Wells against Del Potro
The Swiss maestro missed the last six months of the 2016 campaign due to a knee injury and returned for the 2017 Australian Open . Although Coric's resolve remained and he broke again to lead 4-3, a double-fault allowed Federer to promptly level matters.
Edin Dzeko sends Roma through against Shakhtar and into last eight
It is the first time in over a decade that two Italian teams reach the quarter-finals of the UCL as Juve and Roma are still alive. Roma came out on the front foot, but it was Shakhtar that almost opened the scoring-though it came from a Roma player.
Russian Foreign Ministry spokeswoman Maria Zakharova said on Friday Moscow had already decided on retaliatory measures, which she said Britain would be informed of in the near future.
The statement said: "It is an assault on United Kingdom sovereignty and any such use by a state party is a clear violation of the Chemical Weapons Convention and a breach of global law".
Skripal is a former colonel in Russian military intelligence who was jailed in his country for betraying agents to Britain's MI6 secret service and moved there in a spy swap in 2010.
High-level diplomatic rifts follow a predictable pattern, says Palmer, and this one is no different; everyone knew Russia's move was coming, it was just a question of when.
Bristow told journalists in Moscow on Saturday, "We will always do what is necessary to defend ourselves, our allies and our values against an attack of this sort".
Correspondingly, Labour leader Jeremy Corbyn's position has weakened and he has even been attacked by his own MPs for not giving stronger cross-party backing to May over Russian Federation.
New tensions have also surfaced over the death Monday of a London-based Russian businessman, Nikolai Glushkov.
Trump spoke to reporters at the White House after his administration announced new sanctions on Russian entities for alleged meddling in the 2016 USA presidential election.