March 12 (UPI) -- British Prime Minister Theresa May said the nerve agent used to poison a former Russian spy and his daughter was Russian made and Moscow likely was behind the attack.
She made the comments Monday during a British National Security Council meeting about the poisoning of Sergei Skripal and his daughter Yulia Skripal. The prime minister said the poison was part of a group of nerve agents known as Novichok.
"Based on the positive identification of this chemical agent by world-leading experts at the Defense Science and Technology Laboratory at Porton Down; our knowledge that Russia has previously produced this agent and would still be capable of doing so; Russia's record of conducting state-sponsored assassinations; and our assessment that Russia views some defectors as legitimate targets for assassinations; the government has concluded that it is highly likely that Russia was responsible for the act against Sergei and Yulia Skripal," May said.
U.S. Secretary of State Rex Tillerson said later Monday he talked to his counterparts in Britain and determined their assessment was accurate.
"There is never a justification for this type of attack -- the attempted murder of a private citizen on the soil of a sovereign nation -- and we are outraged that Russia appears to have again engaged in such behavior," a statement attributed to Tillerson's office said. "We agree that those responsible -- both those who committed the crime and those who ordered it -- must face appropriately serious consequences."
The meeting included senior ministers and intelligence chiefs in the British government.
Sergei Skripal, 66, and his daughter Yulia Skripal, 33, were found slumped on a bench following the attack and remain in critical condition, officials said.
The meeting comes days after British Foreign Secretary Boris Johnson warned Russia and denounced the Kremlin's increasingly "malign" influence on global affairs.
"I increasingly think we need to classify them as acts of war," Johnson said to British MPs. "We need to elaborate a new doctrine of response and a new doctrine of deterrence as well."
Monday, Kremlin spokesman Dmitry Peskov said the poisoning didn't involve Russia, "let alone Russia's leadership."
"We've heard no statements from British politicians or officials Russia may be involved in this case somehow. We've seen various insinuations in the British media, which sometimes don't boast objectivity at all," Peskov said, adding "these reports should be taken for their real worth."
Sergei Skripal was granted refuge in Britain in 2010 during a spy swap with other Russian prisoners, after being arrested in 2004 for spying for British intelligence to provide state secrets.
Customers who visited an Italian restaurant around the time of the poisoning have been urged to clean their clothes and any possessions they had with them at the time.