Russian President Vladimir Putin has accused Britain of making baseless allegations against Russia after a former Soviet double agent was among four people found poisoned by a nerve agent in southern England.
Asked in a Fox News interview about the British government's assertion that Russia was behind the Novichok attack on the former spy Sergei Skripal, Mr Putin said the UK had not provided any evidence to back up its claim.
"We would like to get documentary evidence but nobody gives it to us," Mr Putin, speaking through a translator, told the US network after a summit with US President Donald Trump in Finland.
"It's the same thing with the accusations of meddling in the election process in America," he added in reference to claims that Russia interfered in the 2016 US presidential election, which was won by Mr Trump.
The Russian leader suggested the case could be driven by domestic issues in Britain, saying "nobody wants to look into these".
"We just see the ungrounded accusations - why is it done this way? Why should our relationship be made worse by this?"
Mr Skripal and his daughter Yulia collapsed in Salisbury on 4 March after being exposed to Novichok. Both have since recovered.
Then on 30 June, Charlie Rowley and his partner Dawn Sturgess fell ill not far from the Skripal attack after being exposed to the same nerve agent. Ms Sturgess died on 8 July.
Russia has strongly denied poisoning the Skripals, sparking a diplomatic row that has led to tit-for-tat diplomatic expulsions between Britain and its allies and Russia.
Police have not been able to establish whether the Novichok that Mr Rowley and Ms Sturgess were exposed to was from the same batch used against the Skripals, but have said that a possible connection is their main line of inquiry.
Mr Rowley remains seriously ill in hospital but his brother has told the BBC that the 45-year-old fell ill after picking up a discarded perfume bottle.
"What kind of bottle? What is the chemical formula? Who's got it?" Mr Putin said in his interview.