The United States announced a fresh wave of sanctions against Russia on Friday a day ahead of the second anniversary of Moscow's invasion of Ukraine, as President Vladimir Putin hailed Russian "heroes" fighting there.
Ukraine President Volodymyr Zelensky renewed his appeal for swift delivery of air-defence systems and fighter jets, while European Union leaders pledged continued backing for Kyiv.
US President Joe Biden announced sanctions on more than 500 targets to "ensure Putin pays an even steeper price for his aggression abroad and repression at home".
And he renewed his appeal to the US Congress to fund more military aid to Ukraine.
"History is watching," he said. "The failure to support Ukraine at this critical moment will not be forgotten."
Ukraine has been weakened by the blocking of US aid and worsening ammunition shortages.
Putin's message came on Russia's "Defender of the Fatherland Day", a holiday that is an occasion for military pomp and Kremlin-sponsored patriotism.
This year he was able to celebrate Russia's capture of the Ukrainian city of Avdiivka last week and claim further advances along the frontline with Ukraine's troops.
"You are our true national heroes," Putin said in a video message addressed to troops and veterans.
Russia calls new US sanctions 'cynical' interference
"The new illegitimate restrictions are yet another brazen and cynical attempt to interfere in the internal affairs of the Russian Federation," Russia's envoy to the US Anatoly Antonov told state news agencies.
Russia said Friday that new US sanctions were a "cynical" attempt to interfere in its affairs ahead of elections set to extend President Vladimir Putin's term in office next month.