"The two individuals named by the police and CPS are officers from the Russian military intelligence service, also known as the GRU". May said. "It was nearly certainly also approved outside the GRU at a senior level of the Russian state".
British police also released images of the two men, both around 40 years old, who were blamed for the attack in Salisbury on March 4.
Prosecutor Sue Hemming said Wednesday that the U.K.is not asking Moscow to extradite the men because Russian law forbids extradition of the country's citizens.
PHOTO:This undated image taken from the Facebook page of Yulia Skripal on March 8, 2018 allegedly shows Yulia Skripal, the daughter of former Russian spy Sergei Skripal, in an unknown location.
Authorities later determined that they had been poisoned by Novichok, a nerve agent developed by the Soviet Union during the Cold War.
Both of the Skripals survived, but in what police call a tragic effect of the attack, Dawn Sturgess, a 44-year-old mother of three, died on July 8 after being exposed to the same nerve agent.
CBS News correspondent Jonathan Vigliotti reports the police also released surveillance video on Thursday showing the two suspects near the site of the Salisbury poisoning in March.
A senior British police official, Neil Basu, called it "the most significant moment so far in what has been one of the most complex and intensive investigations we have undertaken in counterterrorism policing".More news: Puerto Rico raises death toll from storm Maria to 2975
They left Salisbury and returned to Waterloo Station, arriving at approximately 4.45pm and boarded the London Underground at approximately 6.30pm to London Heathrow Airport. "Russia has made this clear following requests for extradition in other cases".
The CPS said Petrov and Boshirov face charges of conspiracy to murder the ex-spy, and the attempted murder of Skripal, his daughter, and Nick Bailey, a policeman injured in the attack. Russia's charge d'affairs in London Ivan Volodin was summoned to the Foreign Office on Wednesday over the Salisbury incident, the Russian embassy told TASS. May said. She added that Britain's security services would pay closer attention to the GRU and work with allies to "deploy the full range of tools from across our national security apparatus in order to counter the threat posed by the GRU".
More than three months later, the bottle was found by a local man, Charlie Rowley.
Police believe the poison was brought to the United Kingdom from Russian Federation in a Nina Ricci "Premier Jour" perfume bottle with a specially-made poison applicator.
On June 30, two people collapsed in a house in Amesbury, near Salisbury where the Skripals were poisoned with Novichok.
Russian Foreign Ministry spokeswoman Maria Zakharova said the names and images of Petrov and Boshirov "say nothing to us".
British police said Wednesday the case is now part of the Skripal investigation.
The U.S. last month imposed sanctions on Russian Federation, including on electronics, lasers and some oil and gas production technologies, after concluding it was behind the attack on the Skripals. Mr. Rowley brought the box home and his partner, Dawn Sturgess, applied the supposed perfume to her wrists.