Russia has closed the US consulate in St Petersburg and expelled 60 American diplomats in a retaliation to Russian diplomats being expelled from America over the nerve agent attack in the UK.
The poison attack is the first chemical weapon strike on European soil since World War Two, and has pushed tensions between the Kremlin and the West to their highest in decades.
Russia has given the diplomats till April 5 to leave the country and intends to mirror the expulsions from other countries.