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 U.S. 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.
U.S. 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."
'Critical moment'
Putin was speaking a day after U.S. 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 defense.
Duda said that thanks to Biden "we can see that America can keep the world order."
Biden was due to respond to Putin's address at 4:30 p.m. GMT 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.
A top U.S. official reacted to Putin's remarks, dismissing as an "absurdity" his accusations that Russia had been threatened by the West as justification for sending troops into Ukraine on Feb. 24, 2022.
"Nobody is attacking Russia. There's a kind of absurdity in the notion that Russia was under some form of military threat from Ukraine or anyone else," White House National Security Advisor Jake Sullivan told reporters in Warsaw.
Shortly after Putin's speech, Ukraine's presidential chief of staff Andriy Yermak said on Telegram that Moscow was "strategically at a dead end."
"Our goal is to kick them out of Ukraine and punish them for everything," he said.
'Mercilessly killing'
When the Kremlin launched the offensive in Ukraine, its so-called "special military operation" was planned to be a rapid conquest leading to capitulation and the installation of a pro-Russian regime.
Since then, Russia has been forced to give up ground in Ukraine but has kept up a barrage of drone and missile attacks and the military and civilian toll has spiraled.
According to the latest estimates from Norway, the conflict has wounded or killed 180,000 Russian soldiers and 100,000 Ukrainian troops.
Other Western sources estimate the conflict has caused 150,000 casualties on each side.
In Ukraine on Tuesday, President Volodymyr Zelenskyy blasted Russia for "mercilessly killing" civilians in the southern city of Kherson as local officials reported at least five deaths following strikes there.
AFP reporters saw dead bodies covered with plastic sheets or foil blankets on the streets near a bus stop and a supermarket in Kherson.
Kherson is the capital of one of the four regions – along with Donetsk, Luhansk and Zaporizhzhia – that Russia claims to have annexed but has never fully controlled.