A-234 is an organophosphate nerve agent. It was developed in the Soviet Union under the FOLIANT program and is one of the group of compounds referred to as Novichok agents that were revealed by Vil Mirzayanov. In March 2018, the Russian ambassador to the UK, Alexander Yakovenko, claimed to have been informed by British authorities that A-234 had been identified as the agent used in the poisoning of Sergei and Yulia Skripal in Salisbury. Vladimir Uglev, a Russian chemist who worked on the Novichok series of compounds, said he was "99 percent sure that it was A-234" in relation to the 2018 Amesbury poisonings that resulted in the death of Dawn Sturgess and the poisoning of another British national, noting its unusually high persistence in the environment.