The US warned the world should be “chilled to the bone” by the conclusion of the investigations into the Salisbury attack, which identified two Russian nationals as suspects in the Novichok attack.
US President Donald Trump, German Chancellor Angela Merkel, French President Emmanuel Macron and Canadian Prime Minister Justin Trudeau issued a joint statement on Thursday agreeing with the British assessment that the operation was “almost certainly approved at a senior government level” in Moscow.
On Wednesday, two Russian nationals, said to be members of Russia’s military intelligence service the GRU, were identified as suspects by police investigating the poisoning of former spy Sergei Skripal in March.
GCHQ head Jeremy Fleming warned that Russia poses an "active" threat during a speech in Washington.
He called on the international community to reject the Kremlin's "brazen determination to undermine the international rules-based order".
‘Disgusting anti-Russian hysteria’
Russia claimed that the UK was trying to unleash “disgusting anti-Russian hysteria” during talks at the United Nations.
Diplomat Vasily Nebenzya told the UN security council: "I'm not going to go through the list of this whole unfounded and mendacious cocktail of facts.
"London needs this story for just one purpose - to unleash a disgusting anti-Russian hysteria and to involve other countries in this hysteria."
Mr Skripal and his daughter Yulia were left critically ill after being exposed to the nerve agent Novichok in Salisbury in March.
Detectives believe it is likely the two suspects travelled under aliases and that Alexander Petrov and Ruslan Boshirov are not their real names.
Officers have formally linked the attack on the Skripals to events in nearby Amesbury when Dawn Sturgess, 44, and her partner Charlie Rowley, 45, were exposed to the same nerve agent.
Ms Sturgess died in hospital in July, just over a week after the pair fell ill.