The US president said his government was not aware of whether or not Alexei Navalny was killed by the Russian government but that Vladimir Putin was responsible for his death. Other world leaders have also laid responsibility for the opposition leader"s death firmly at the feet of the Russian president Russian activist and Putin critic Alexei Navalny dies in prison Global reaction to Alexei Navalny’s death – latest updates How will Russia remember Alexei Navalny? – video explainer