The US has said it will impose fresh sanctions on Russia after determining it used nerve agent against a former Russian double agent living in the UK.
Sergei Skripal and his daughter Yulia were found unconscious on a bench in the city of Salisbury in March.
The attack left the pair seriously ill, but they recovered after several weeks of hospital treatment.
A UK investigation blamed Russia for the attack, but the Kremlin has strongly denied any involvement.
In a statement released on Wednesday, the US state department confirmed it was implementing measures against Russia over the incident.
Spokeswoman Heather Nauert said it had been determined that the country “has used chemical or biological weapons in violation of international law, or has used lethal chemical or biological weapons against its own nationals.”