The clock serves as a metaphor for how close humanity is to destroying the planet. The last time it was at two minutes to midnight was in 1953 when the United States and Soviet Union were testing hydrogen bombs.
Scientists on Thursday moved ahead by half a minute the symbolic Doomsday Clock, saying the world was at its closest to annihilation since the height of the Cold War due to world leaders' poor response to threats of nuclear war.
It was the second occasion the timepiece, created by the Bulletin of the Atomic Scientists as an indicator of the world's susceptibility to cataclysm, was moved forward since the 2016 election of US president Donald Trump.
At two minutes to midnight, the clock is at its closest to catastrophe since 1953, due to dangers of a nuclear holocaust from North Korea's weapons program, US Russian entanglements, South China Sea tensions, and other factors, the Chicago-based group said in a statement.
"Hyperbolic rhetoric and provocative actions on both sides have increased the possibility of nuclear war by accident or miscalculation," the group said of North Korea's nuclear program and the Trump administration's response to it.
Unchecked dangers linked to climate change were another factor scientists cited for moving theclock forward.
An overarching concern was what scientists described as the demise of diplomacy under the Trump administration.
"International diplomacy has been reduced to name-calling, giving it a surrealistic sense of unreality that makes the world security situation ever more threatening,” they said.
Turn back the clock
To rewind the clock, scientists recommended Trump refrain from provocative rhetoric regarding North Korea, the two countries open multiple communication channels and the world community seek a cessation of North Korea's nuclear weapon and ballistic missile tests.
The bulletin was founded by scientists who helped develop the United States' first atomic weapons. Its Science and Security Board decides on the clock's hands in consultation with its Board of Sponsors, which includes 15 Nobel laureates.
When the clock was created in 1947, it was set at 7 minutes to midnight.
Last year the clock's hands were pushed forward 30 seconds to their second closest point to midnight - two minutes and 30 seconds - after Trump's statements regarding the proliferation of nuclear weapons and the prospect of actually using them.
In 2016, the clock remained unmoved, its hands staying at three minutes to midnight.