Russian leaders reports successful trial of Burevestnik weapon, notes US has not ratified Comprehensive Nuclear Test Ban, Russia could cancel its own ratification

Antonio Guterres reiterates call for banning atomic weapons' tests, with 1996 global treaty yet to take effect while awaiting ratification by several countries, including Israel

Amid talks over inclusion of China in new deal, US negotiator says 'we do remain far apart on a number of key issues'

Top security agency officials said to hold talks on possible test ahead of negotiations with Beijing and Moscow over weapons treaty

Moscow tells international officials communication issues have knocked offline 2 locations near missile testing site where deadly explosion killed several scientists