International chemical weapons experts are scheduled to arrive in Britain on March 19 to get samples from the nerve agent involved in the poisoning of a Russian ex-spy in England.
Experts from the Organization for the Prohibition of Chemical Weapons (OPCW) are expected to collect samples of the substance, which Britain has identified as Novichok -- a Soviet-designed military-grade nerve agent.
"These [samples] will then be dispatched to highly reputable international laboratories selected by the OPCW for testing, with results expected to take a minimum of two weeks," Britain's Foreign Office said.
Britain and its allies have blamed Moscow for the March 4 attack in Salisbury that left Sergei Skripal and his daughter, Yulia, in critical condition after exposure to a nerve agent.
Skripal is a former Russian military intelligence officer who betrayed numerous Russian agents to Britain. He and his daughter continue to fight for their lives after they were discovered collapsed on a bench in Salisbury.
The poisoning prompted Britain to announce the expulsion of 23 Russian diplomats, with Moscow saying it would reciprocate by expelling the same number of British diplomats.
Russian President Vladimir Putin rejected allegations that his country was behind the attack.
Russia 'Stockpiling' Nerve Agent
British Foreign Secretary Boris Johnson on March 18 accused Russia of stockpiling the nerve agent used in the attack.
"We actually have evidence within the last 10 years that Russia has not only been investigating the delivery of nerve agents for the purposes of assassination, but has also been creating and stockpiling Novichok," Johnson told the BBC.
The Russian ambassador to the European Union, Vladimir Chizhov, told the BBC on March 17 that Russia halted "production of any chemical agents back in 1992" and that a British research facility could have been the source of the toxin used in the poisoning of Skripal.
Johnson accused the Russians of "smug sarcasm and denial" and said the international community was behind Britain.
Moscow's "malign, disruptive behavior" internationally was the reason why allies were "inclined not to give Russia the benefit of the doubt," he added.
In a joint statement with Britain on March 15, the leaders of the United States, France, and Germany condemned the attack as "an assault on U.K. sovereignty."
"This use of a military-grade nerve agent, of a type developed by Russia, constitutes the first offensive use of a nerve agent in Europe since the Second World War,” the leaders said.
Johnson is expected to brief his counterparts on developments in the poisoning case during a meeting of EU foreign ministers and NATO chief Jens Stoltenberg in Brussels on March 19.