President Volodymyr Zelenskiy urged the West to stop playing around with Russia and impose tougher sanctions on Moscow to end its "senseless war" in Ukraine, adding his country would remain independent, the only question was at what price.
Zelenskiy's criticism of the West has mounted in recent days as the European Union moves slowly towards a possible Russian oil embargo and as thousands of Russian forces try to encircle two key eastern cities of Sievierodonetsk and Lysychansk.
Three months into its invasion of Ukraine, Russia has abandoned its assault on the capital Kyiv and is trying to consolidate control of the industrial eastern Donbas region, where it has backed a separatist revolt since 2014.
On Wednesday, he (Zelenskiy) savaged suggestions that Kyiv make concessions to bring peace, saying the idea smacked of attempts to appease Nazi Germany in 1938.
Western military analysts see the battle for Sievierodonetsk and Lysychansk as a potential turning point in the war after a shift in momentum towards Russia following the surrender of Ukraine's garrison in Mariupol last week.
"Ukraine will always be an independent state and it won't be broken. The only question is what price our people will have to pay for their freedom, and what price Russia will pay for this senseless war against us," said Zelenskiy in a late-night address on Thursday.
"The catastrophic unfolding events could be still stopped if the world treated the situation in Ukraine as if it were facing the same situation, if the powers that be did not play around with Russia but really pressed to end the war."
Zelenskiy complained about disagreements within the EU on more sanctions against Russia and asked why some nations were being allowed to block the plan.
The EU is discussing a sixth round of punitive measures, including an embargo on Russian oil imports. Such a move requires unanimity but Hungary opposes the idea for now on the grounds its economy would suffer too much.
"How many more weeks will the European Union try to agree on a sixth package?" Zelenskiy asked, noting Russia was receiving one billion euros a day from the 27-nation bloc for energy supplies.
"Pressure on Russia is literally a matter of saving lives. Every day of procrastination, weakness, various disputes or proposals to 'pacify' the aggressor at the expense of the victim merely means more Ukrainians being killed."
Zelenskiy's comments mark the second day in a row that he has sharpened his criticism of the world's approach to the war.
On Wednesday, he savaged suggestions that Kyiv make concessions to bring peace, saying the idea smacked of attempts to appease Nazi Germany in 1938.