President Vladimir Putin on Tuesday suspended Moscow's participation in a nuclear arms treaty with Washington and accused the West of escalating the conflict in Ukraine, ahead of a key speech by US President Joe Biden.
In his scathing state of the nation address ahead of the first anniversary of the campaign in Ukraine, Putin also vowed that Russia would keep fighting in Ukraine and "systematically" achieve its aims. The Russian leader accused Western powers of wanting "to be done with us once and for all", but said increasingly stringent international sanctions on Russia "will not succeed".
He said Moscow would no longer take part in the New START treaty for nuclear disarmament but would not pull out of the agreement altogether. The 2010 deal is the last remaining arms control treaty between the world's two main nuclear powers but it has frayed in recent years, with the two sides accusing each other of not complying with it.
US Secretary of State Antony Blinken said Russia's decision was "deeply unfortunate and irresponsible" but that Washington was still willing to talk about the issue. NATO Secretary General Jens Stoltenberg said the move meant that "the whole arms control architecture has been dismantled".
Putin was speaking a day after US President Joe Biden made a surprise visit to Kyiv in which he promised additional arms deliveries for Ukraine and "unwavering" support.On a visit to NATO member Poland on Tuesday, Biden told President Andrzej Duda he was coming "at a critical moment".
"NATO is stronger than it's ever been," Biden said, reaffirming Washington's "iron-clad" commitment to the Western alliance's principle of collective defence.
Duda said that thanks to Biden "we can see that America can keep the world order". Biden is due to respond to Putin's address at 1630 GMT on Tuesday with his own speech in Warsaw's historic Royal Castle.
On Wednesday, he is due to meet with the leaders of nine eastern NATO members which have been staunch supporters of Ukraine and where there are fears of the conflict spilling over.