A nerve agent attack on a former Russian spy raises broader questions about Russia’s illegal use of chemical weapons, and Britain’s allies should respond appropriately, Prime Minister Theresa May said on Wednesday.

Britain said that Russia was culpable for the poisoning of Sergei Skripal and his daughter in the English city of Salisbury. Russia denies involvement.

“While we rightly, initially focus on the use of this nerve agent here in the UK and its impact on us here in the UK, this is about the illegal use of chemical weapons by the Russian state,” May told parliament.

“It is about an illegal program to develop those chemical weapons by the Russian state, and we will leave no stone unturned in order to work with our allies to ensure that we respond appropriately to that.”

Reuters