In the joint statement, the leaders said: "We have full confidence in the British assessment that the two suspects were officers from the Russian military intelligence service, also known as the GRU, and that this operation was nearly certainly approved at a senior government level".
His remarks are the furthest the British government has gone yet in attributing direct blame on Putin for the attempt by two Russian military intelligence officers to murder Sergei and Yulia Skripal with the military grade nerve agent in March. Det Sgt Nick Bailey fell ill responding to the incident in Salisbury.
"CCTV shows them in the vicinity of Mr Skripal's house and we believe that they contaminated the front door with Novichok", Basu said.
Neil Basu, Head of Counter Terrorism policing, said the two suspects were travelling under aliases but were around 40 years old and had genuine Russian passports.
Later, Prime Minister Theresa May said the men were officers in Russia's military intelligence service, the GRU, acting on orders from senior Kremlin figures, accusations Moscow has rejected as unacceptable.
"This was not a rogue operation, " she told lawmakers after police released photos of the suspects as they traveled through London and Salisbury before flying back to Moscow from Heathrow Airport on the evening of March 4, hours after the Skripals were poisoned.
The case has echoes of the murder of Russian dissident Alexander Litvinenko in London in 2006.
He said the pair flew into London's Gatwick Airport from Moscow two days before the Salisbury attack, on Friday, March 2, and stayed at a hotel in the east of the capital.
If according to the British side, these people have come from Russian Federation, they must have received British visas, so, please, "fingers at the table". "I don't understand why this was done and what sort of signal the British side is sending".
London and its allies expelled dozens of Russian diplomats after the poisoning, prompting a tit-for-tat response from Moscow and plunging relations to a new low.More news: Tesla in turmoil: Stock plunges after executive shakeup
US Ambassador Nikki Haley said everyone should be "chilled to the bone" with the findings.
Mr Basu would not say whether police believe the suspects worked for Russian security services but, he said, "this was a sophisticated attack across borders".
They spent weeks critically ill in hospital but have since been discharged.
Soon the two men recorded at the railway station in Salisbury at 11:48 am on Sunday, March 4.
Police also said the men's hotel room had returned dangerously-high levels of Novichok when police conducted tests for it. They are also charged with illegal use and possession of a chemical weapon.
She said Yulia told her that she felt fine, was "recovering" and went jogging in the morning.
Wiltshire local woman Dawn Sturgess died after inadvertently spraying herself with the Novichok virus which was inside a discarded perfume bottle.
On 30 June 2018 a similar poisoning of two British nationals in Amesbury, seven miles from Salisbury, involved the same nerve agent.
Therefore, after 6 months of attacks the Prime Minister is pressing for the Kremlin to be hit by fresh global sanctions, after two Russian spies were named as suspects for Novichok attack in Salisbury. She has criticized London for turning down Moscow's request to see the case files.
Russian defense and security analyst Pavel Felgenhauer said authorisation to attack the Skripals had also likely come "from the very top".
Mr Basu said: "We do not believe Dawn and Charlie were deliberately targeted, but became victims as a result of the recklessness in which such a toxic nerve agent was disposed of".