Prime Minister Theresa May has said the two Russian men suspected of the Salisbury Novichok poisoning should be “brought to justice”, ahead of a meeting with President Vladimir Putin.
Mrs May is expected to discuss the attack with Mr Putin during one-to-one talks on the sidelines of the G20 summit.
In an interview with the BBC, Mrs May said the poisoning was a “despicable and irresponsible act” and Russia “needs to recognise its acts and stop acting in this way”.
Russia has denied any involvement in the attack, which took place in March 2018.