UNITED NATIONS, June 3, 2016 (Xinhua) -- Liao Jinrong(1st R), director-general of the international cooperation department at China's ministry of public security, speaks during the United Nations Chiefs of Police Summit (UNCOPS), a historic gathering of more than 100 police leaders from around the world, at the UN headquarters in New York, June 3, 2016. UN police has become a central pillar of UN peace operations, said UN Deputy Secretary-General Jan Eliasson here on Friday. (Xinhua/Li Muzi)