It marks the first time that US President Biden has assigned a specific portfolio to Vice President Harris, who is seen as representing a younger generation in the Democratic Party and has been constantly at his side since they entered office.
PM Nikol Pashinyan, who accuses the military of an attempted coup, has faced opposition calls to step down ever since he signed a November 10 peace deal that saw Azerbaijan reclaim control over large parts of Nagorno-Karabakh and surrounding areas.