(CNN) UK Prime Minister Theresa May on Sunday lauded Europe's response to Russia's "reckless" use of chemical weapons.

"The past year has tragically proven those threats to be ever more real -- not least through the reckless use of a chemical weapon on our own streets by two agents of the Russian Intelligence Services. But it has also proven our commitment to respond -- exactly as I said we would," May said at the Lord Mayor's Banquet, according to a preview of her speech released earlier in the day.

"Together with our allies, in response to the attack in Salisbury, we coordinated the largest ever collective expulsion of Russian intelligence officers, fundamentally degrading Russian intelligence capability for years to come. And our law enforcement agencies, through painstaking investigations and cooperation with our allies, produced the irrefutable evidence that enabled our Crown Prosecution Service to bring charges against those responsible."

The comments come in response to the poisoning of former Russian double agent Sergei Skripal and his daughter, Yulia, who were found slumped on a park bench in the southern English city of Salisbury on March 4. They had been exposed to Novichok , a rare Soviet-era nerve agent that few scientists outside of Russia have ever dealt with.

Since the attack on the Skirpals, Russia and the UK have been embroiled in a bitter diplomatic fight.

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