NATO Secretary-General Jens Stoltenberg said on Tuesday Russia's decision to suspend participation in the latest START bilateral nuclear arms control treaty made the world a more dangerous place, and he urged Moscow to reconsider.
He spoke at a news conference held at NATO headquarters in Brussels after Russian President Vladimir Putin delivered a warning to the West over the war in Ukraine and announced its decision on the New START treaty.
The treaty between Moscow and Washington, signed in 2010, limits the number of atomic warheads the world's two biggest nuclear powers can deploy and is due to expire in 2026.
"More nuclear weapons and less arms control makes the world more dangerous," Stoltenberg, standing alongside Ukrainian Foreign Minister Dmytro Kuleba and EU foreign policy chief Josep Borrell, told reporters.
Replying to Putin's accusations that the West was trying to destroy Russia, Stoltenberg said Moscow was the aggressor in Ukraine where it launched a invasion almost a year ago.
"It is President Putin who started this imperial war of conquest ... As Putin made clear today, he's preparing for more war ... Putin must not win ... It would be dangerous for our own security and the whole world," Stoltenberg added.
"I regret the decision by Russia to suspend its participation in (the) New START programme".
In Athens on Tuesday, U.S. Secretary of State Antony Blinken said Russia's decision was irresponsible and the United States would watch carefully to see what Moscow actually does.
(Reporting by Bart Meijer, Benoit Van Overstraeten and Andrew Gray; editing by Andrew Heavens and Mark Heinrich)