The Doomsday Clock has remained at 100 seconds to midnight for a third year in a row as scientists said the world is "no safer" than it was this time last year.
Maintaining last year's setting means the clock's keepers believe the threat of global apocalypse has not cooled off in the past 12 months.
Rachel Bronson, president and chief executive of the Bulletin of the Atomic Scientists, said: "This year, in our statement, the science and security board highlights several bright spots and many disturbing trends.
"The board describes a mixed-threat environment, one with positive developments counteracted by accelerating negative ones.
"Today, the members of the science and security board deem the world to be no safer than it was last year at this time, and therefore have decided to set the Doomsday Clock at 100 seconds to midnight.
"The Doomsday Clock continues to hover dangerously, reminding us how much work is needed to ensure a safer and healthier planet. We must continue to push the hands of the clock away from midnight."
Australian Associated Press