Russian Foreign Minister Sergei Lavrov said on Friday Russia will expel British diplomats in response to London’s decision to expel 23 staff at the Russian embassy in London.

Asked by a Reuters reporter, at a summit on Syria in the Kazakh capital, if Russia planned to expel British diplomats, Lavrov replied: “We will, of course.” He did not give any further details.

On Wednesday, May expelled 23 Russian diplomats over the poisoning of former double agent Sergei Skripal and his daughter Yulia in the English city of Salisbury, as the standoff with Moscow — which denies responsibility — escalated.

Britain also suspended high-level contacts, including for the World Cup which Russia is due to host in June and July.

Moscow has denied any involvement, and some chemical experts have said the nerve agent may have been stolen in the aftermath of the collapse of the former Soviet Union, when security at chemical sites was allegedly lax.