- Video report by ITV News correspondent Emma Murphy
Vladimir Putin dismissed as "nonsense" and "drivel" claims of Russian involvement in the Salisbury spy poisoning as he was re-elected president.
As he celebrated winning another six years in office, Mr Putin said Sergei Skripal and his daughter Yulia would have died instantly if they had been attacked with a nerve agent.
British authorities believe Novichok was used in the attack and inspectors from the Organisation for the Prohibition of Chemical Weapons will arrive in the UK on Monday to test the nerve agent - although the results will take at least two weeks.
Boris Johnson, who will update European Union counterparts on developments in the attack during a meeting in Brussels on Monday, has accused Russia of stockpiling Novichok for a decade in breach of international rules.
Making his first public comments on the incident, President Putin said he learnt about the "tragedy" from the media and that Russia was ready to cooperate with the investigation.
"The first thing that comes to my mind is that should it really be a warfare agent, people would have died instantly," he said. "It is an obvious fact.
"Russia does not possess such agents. We have destroyed all our chemical arsenals under control of international observers."
Mr Putin said it was "complete drivel, rubbish, nonsense" that such state sponsored action would be taken by Russia ahead of the election and the upcoming football World Cup.
He added: "We are ready for cooperation and said that immediately. We are ready to take part in all necessary probes but the will of the other side is needed for that. So far, we see none."
Mr Putin secured a fourth term amid widespread claims of electoral fraud.
Moscow has mocked the UK's response to the attack, saying it had fuelled an increase in support for President Putin in the election.
The Foreign Secretary said Russia has investigated ways of delivering nerve agents for assassination over the last 10 years in a breach of international rules.
Russia's ambassador to the EU, Vladimir Chizhov, suggested the Novichok may have come from the Porton Down laboratory, which is about eight miles from Salisbury.
Sweden and the Czech Republic denied Russian suggestions they may have been the source of the nerve agent.
The national security council will meet in the coming days to discuss Moscow's tit-for-tat response to the UK's expulsion of 23 Russian diplomats.
Mr Skripal, a former double agent, and his daughter may have been exposed to a deadly nerve agent through his car's ventilation system, US media has reported.
The pair are still fighting for their lives after being exposed to Novichok two weeks ago in the Wiltshire city.
Counter-terrorism police renewed their appeal for sightings of Mr Skripal's burgundy BMW 320D saloon car in Salisbury on the morning of Sunday March 4.