The leaders of France, Germany, the US and UK have issued a joint statement on the nerve agent attack in the UK, saying Russian responsibility was the "only plausible explanation", wrote BBC.
It condemned the "first offensive use of a nerve agent in Europe since the Second World War", calling it an assault on UK sovereignty.
The UK has expelled 23 Russian diplomats in the wake of the incident.
PM Theresa May on Thursday visited the site of the attack in Wiltshire.
"We do hold Russia culpable for this brazen, brazen act and despicable act," she said.
The nerve agent was used on a former Russian spy and his daughter in Salisbury. Both remain in a critical condition in hospital.
The joint statement said: "It is an assault on UK sovereignty and any such use by a State party is a clear violation of the Chemical Weapons Convention and a breach of international law. It threatens the security of us all."
The nations urged Russia to "address all questions related to the attack" and provide all details about the nerve agent used.
It added: "Our concerns are also heightened against the background of a pattern of earlier irresponsible Russian behavior.
"We call on Russia to live up to its responsibilities as a member of the UN Security Council to uphold international peace and security."