U.N. Secretary-General Ban Ki-Moon (in white-and-blue vest) joins other leaders at the 2015 International Women's Day March at Dag Hammarskjold Plaza on March 8 in New York City. Michael Stewart/WireImage/Getty Images hide caption

itoggle caption Michael Stewart/WireImage/Getty Images

U.N. Secretary-General Ban Ki-moon, who received the report on Syria's chemical weapons over the weekend from professor Ake Sellstrom, expressed his "profound shock and regret" at its findings. Paulo Filgueiras/UN Photo hide caption

itoggle caption Paulo Filgueiras/UN Photo