More than 150 Russian diplomats have been expelled by 29 countries and North Atlantic Treaty Organisation after the British government convinced global allies that there was no plausible alternative explanation than for Russia to have carried out the attack.
Four Russian diplomats expelled from Germany arrived back in Moscow on the weekend, Russia's embassy in Berlin said, ahead of a Monday deadline imposed on Moscow.
Putin's spokesman Dmitry Peskov told reporters that Britain will have to apologize to Russian Federation for its "mad accusations" that "have no foundation whatsoever".
Moscow, which denies any involvement, has requested a meeting at the Hague.
Nerve agents act immediately. "Regardless of what one thinks about Russian Federation, my study of worldwide law taught me a different way to deal with other states", Laschet, premier of the state of North Rhine-Westphlia, said on Twitter.More news: Max Allegri 'tells Roman Abramovich' he wants to take over at Chelsea
"I would like to inform you, although we have already told about that, we are convening a OPCW Executive Council session tomorrow to look into the situation in detail", Putin said after talks with Turkish President Recep Tayyip Erdogan in Ankara.
The relationship between the USA and Russia is strained after Trump ordered the diplomats' expulsion and the closing of the Seattle consulate after the attack last month on a former Russian spy in the U.K. Putin reciprocated, expelling US diplomats and closing the St. Petersburg consulate.
President Recep Tayyip Erdoğan on Tuesday said Turkey and Russian Federation have finalized the deal for the purchase of S-400 missile defense systems, adding that Russian Federation has proved its sincerity by accepting for an early delivery.
Police said they had been exposed to a nerve agent.
A Foreign Office spokesman called the meeting a "diversionary tactic, meant to undermine the work of the OPCW in reaching a conclusion".More news: US Open champion Stephens wins Miami Open title
The request came after Moscow received and analysed samples of the Novichok agent used in the attack.
He said there was no known antidote for the "extremely toxic substance" and they had not provided one for the Skripals, who were stricken by the nerve agent after it was likely smeared on the door of this home.
The global chemical weapons watchdog agency has said it will meet Wednesday to discuss Britain's USA -backed allegation that Russian Federation is responsible for the poisoning of a former double agent in England.
Filatov said Tuesday that if the United Kingdom does not show evidence, "there are ample grounds to assume that we are dealing with a grand scale provocation organized in London aimed to discredit Russian Federation".
He insisted that "serious experts and "leaders of a whole number of countries" were questioning Britain's account of the crime". Russian Federation requested the meeting and has demanded an "unbiased investigation" by the Organization for the Prohibition of Chemical Weapons (OPCW).More news: Oklahoma teachers chalk cars to spread message about needed funding
Deputy Foreign Minister Alexander Grushko in comments relayed by Russian news agencies on Tuesday called Skripal's poisoning a "provocation arranged by Britain" in order to justify high military spending because "they need a major enemy".