U.N. Secretary-General Ban Ki-moon, pictured during a 2014 visit to Haiti to inaugurate a sanitation campaign. On Thursday, he issued an apology that Haitians have been demanding for six years. Hector Retamal/AFP/Getty Images hide caption
Ban Ki-Moon
UN Secretary General Ban Ki-Moon (left) and Israeli Prime Minister Benjamin Netanyahu at a news conference at the prime minister's office in Jerusalem on Tuesday. Li Rui/Xinhua /Landov hide caption
Babacar Gaye has been forced to resign from his post leading the U.N.'s peacekeeping mission in the Central African Republic. He's seen here in 2012, when he led the U.N.'s force in Syria. Hazim/Xinhua /Landov hide caption
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
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
Ai Weiwei FREDERIC J. BROWN/AFP/Getty Images hide caption