The head of the world chemical arms watchdog expressed "grave concern" on Thursday after Germany said Russian opposition leader Alexei Navalny had been poisoned with the nerve agent Novichok.
Organization for the Prohibition of Chemical Weapons (OPCW) Director-General Fernando Arias added that the Hague-based body was ready to help any member country that asked for its assistance.
"Under the Chemical Weapons Convention, any poisoning of an individual through the use of a nerve agent is considered a use of chemical weapons. Such an allegation is a matter of grave concern," Arias said in a statement.
The OPCW chief added that the "use of chemical weapons by anyone under any circumstances" was "reprehensible and wholly contrary to the legal norms established by the international community."
"The OPCW continues to monitor the situation and stands ready to engage with and to assist any states parties that may request its assistance," Arias added.
Germany said on Wednesday that it was going to contact the OPCW about the case but did not say if it would seek its help, as it is entitled to under the Chemical Weapons Convention.