Moscow will expel British diplomats in response to London's move to kick out 23 Russian officials over the poisoning of ex-double agent Sergei Skripal, Russian Foreign Minister Sergei Lavrov said Friday.
Presidential spokesman Dmitry Peskov earlier said Vladimir Putin would ultimately choose the option that "most suits Moscow's interests".
Geopolitical tensions are mounting since the poisoning of ex-spy Sergei Skripal and his daughter in the English city of Salisbury earlier this month, in what Western powers see as the latest sign of increasingly aggressive Russian meddling overseas. British police said they were treating Glushkov's death as unexplained, but did not think it was linked to the attack on the Skripals. A report in the Telegraph says it was put in the suitcase of Skripal's daughter before she left Russian Federation for Britain to see her father.
Russian Federation has insisted it is ready to cooperate in investigating the attack in Salisbury if Britain reciprocates by sharing the evidence it holds - and has dismissed accusations against it as "propaganda" by the United Kingdom government.
Russian Federation has repeatedly dismissed the UK's accusations as "unfounded" and warned it would retaliate over the expulsion of its diplomats. In an attempt to decide how to proceed, London has joined the anti-Russian campaign of how to contain Russia, the Russian Ambassador to London believes.
Russia's envoy at the worldwide chemical weapons watchdog says Britain and the US both have access to the nerve agent used in the poisoning of the ex-spy in Britain.
An 83-year-old Russian whistleblower who helped develop Novichok told the AP on Friday that no other country could have used that particular nerve agent to poison a former spy. He also cast doubt on the possibility that the nerve agent was sent through the mail or was placed in luggage that Skripal's daughter brought with her from Russian Federation to Britain.
Vil Mirzayanov, who now lives in New Jersey, is quoted in Novaya Gazeta as saying it's unlikely the nerve agent came from another former Soviet country as Russians have suggested. "There is to be no Russophobia as a result of what is happening".
He said even the name Novichok was a "Western invention" and that Russian Federation never gave it a name.
May told Turnbull that she visited Salisbury on Thursday and that the act "represented an unlawful use of force by the Russian state against the U.K".
British Defence Secretary, Gavin Williamson, sparked particular outrage in Moscow with his blunt comment on Thursday that "Russia should go away, it should shut up".
Mr Lavrov said: "I guess he wants to go down in history with some bombastic statements ..."
The leader of Britain's main opposition party says the government shouldn't rush to blame Moscow for the nerve agent poisoning of a former spy.