US officials have accused Russia of using chemical weapons in Ukraine, violating international laws. They claim that the choking agent chloropicrin was used to make ‘battlefield gains’. The Kremlin has yet to respond but has denied similar allegations previously. Although in 2017 Russia said it had destroyed all of its Cold War-era stockpile in 2017, it faces accusations of incomplete declarations and subsequent chemical attacks, including the Salisbury attack and Navalny poisoning. Reports suggest Russian forces deployed tear gas grenades, resulting in Ukrainian casualties. Joe Biden has warned of severe consequences if the accusations are proved, and the USA has sanctioned Russian state bodies and firms allegedly linked to biological and chemical weapons programmes. Meanwhile, Human Rights Watch has called for a war crimes investigation, alleging Russian forces executed over a dozen surrendering Ukrainian troops a few months ago.