FILE PHOTO: Former U.S. Ambassador to the United Nations John Bolton speaks at the Conservative Political Action Conference (CPAC) in Oxon Hill, Maryland

FILE PHOTO: Former U.S. Ambassador to the United Nations John Bolton speaks at the Conservative Political Action Conference (CPAC) in Oxon Hill, Maryland

US national security adviser John Bolton speaks at the Conservative Political Action Conference on February 24, 2017. Photo: Reuters/Joshua Roberts

March 23, 2018 5:15 PM (UTC+8)