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".
Earlier in the United Kingdom found that the assassination of former Russian intelligence officer Sergei Skripal and his daughter Julia in Salisbury with the use of poison the Newcomer involved in the Russian Grushnikov Ruslan Bashirov and Alexander Petrov.
Prime Minister Theresa May told lawmakers that British intelligence services have concluded the two men were officers of Russia's GRU military intelligence service. May added that the operation was "approved at a senior level of the Russian state".
Prosecutors deem it futile to apply to Russian Federation for the extradition of the two men, but a European Arrest Warrant has been obtained and the authorities are also seeking the assistance of Interpol.
But assistant commissioner Neil Basu, head of counterterrorism at London's Metropolitan Police, conceded it was "very, very unlikely" police would be in a position to arrest them any time soon, though he said "we will never give up".
Police and prosecutors announced they had enough evidence to charge the men, named as Alexander Petrov and Ruslan Boshirov, over the poisoning in March.
Ushakov pointed to the fact that British authorities mentioned that they think the men's names are aliases and wondered "why this has been done and what kind of a message" Britain is trying to send to the Russian government.
Police say both men, who are about 40 years old, flew from Moscow to London on Russian passports two days before the Skripals were poisoned on March 4. They spent weeks hospitalized in critical condition and are now recovering in a secret location for their own protection.
The Kremlin is denying that it played a role in the poisoning of a former Russian spy in a British city, saying that Britain is not sharing any intelligence with it.
British authorities have issued European arrest warrants for Alexander Petrov and Ruslan Boshirov, two suspected members of Russian military intelligence.
Britain has said it is not going to seek the men's extradition because Russian law does not allow for the extradition of its nationals to be tried overseas. She has criticized London for turning down Moscow's request to see the case files.
In a speech in Washington on Thursday, Jeremy Fleming, Director of the GCHQ eavesdropping intelligence agency, said his staff had helped the "painstaking and highly complex investigation" into identifying those responsible for the Salisbury poisonings and action would now be taken.
Afterwards they made their way to the City Stay Hotel in Bow, east London, for the first of their two-night stay.
The men stayed at a hotel in London and travelled from Waterloo train station before being captured again on CCTV at Salisbury on March 4, the day the Skripals were attacked on March 4. Basu said that traces of Novichok were found in a room, but in too small a quantity to be harmful. They flew out on March 4, hours after the Skripals were found unconscious.
Police say they believe the nerve agent used to poison former Russian spy Sergei Skripal and his daughter was smuggled to Britain in a counterfeit Nina Ricci perfume bottle and applied to the front door of Skripal's house.
More than three months later, the bottle was found in nearby Amesbury by a local man, Charlie Rowley.
Dawn Sturgess, 44, became an indirect casualty of the poisoning and she died after she touched the poisoned item with her hand.
The Organisation for the Prohibition of Chemical Weapons confirmed Tuesday that Rowley and Sturgess were also exposed to Novichok.