Russia announcement on New START 'deeply unfortunate and irresponsible': Blinken

Russia's decision to suspend participation in a nuclear arms control treaty was irresponsible and the United States will watch carefully to see what Moscow actually does, U.S. Secretary of State Antony Blinken said on Tuesday.

"The announcement by Russia that it's suspending participation is deeply unfortunate and irresponsible," Blinken told reporters in Athens. "We'll be watching carefully to see what Russia actually does. We'll of course make sure that in any event, we are postured appropriately for the security of our own country and that of our allies."

President Vladimir Putin on Tuesday delivered a nuclear warning to the West over Ukraine, suspending a bilateral nuclear arms control treaty, announcing new strategic systems had been put on combat duty and warning that Moscow could resume nuclear tests.

Putin said that Russia was suspending participation in the New START Treaty, the last major arms control treaty between Moscow and Washington. It limits the number of nuclear warheads the world's two biggest nuclear powers can deploy and is due to expire in 2026.

Blinken left the door open to resuming negotiations at any time.

"We remain ready to talk about strategic arms limitations at any time with Russia, irrespective of anything else going on, in the world or in our relationship," Blinken said.

The world expects the two largest nuclear powers to act responsibly, he added.