Ukraine’s president says 31,000 soldiers have been killed since Russia's full-scale invasion began two years ago.
Volodymyr Zelensky would not give the number of wounded or missing as that would help Russian military planning.
But he said the death toll is lower than estimates given by Russian president Vladimir Putin’s government.
His comments come after the defence minister said half of all Western aid for Ukraine has been delayed, costing lives and territory.
Speaking at a forum in Kyiv, Zelensky said: “Thirty-one thousand Ukrainian military personnel have been killed in this war.
“Not 300,000, not 150,000, not whatever Putin and his deceitful circle have been lying about.
“But nevertheless, each of these losses is a great sacrifice for us.”
He also said that “tens of thousands of civilians” had been killed in occupied areas of Ukraine, but said that no exact figures would be available until the war was over.
“We don’t know how many of our civilians they killed. We don’t,” he said.
It’s the first time that Kyiv has confirmed the number of its losses since the start of Russia’s war against Ukraine on February 24, 2022.
Last August, The New York Times reported that Ukrainian forces had suffered 70,000 deaths and between 100,000 to 120,000 injuries since the start of the full-scale war, citing unidentified US officials.
Russia has provided few official casualty figures. The most recent data from the Defence Ministry, published in January 2023, pointed to just over 6,000 deaths, although reports from US and UK put causalities significantly higher.
Ukraine is currently experiencing a variety of setbacks in its mission to drive Russia from its territory.
Umerov said that the lack of supplies put his nation at a further disadvantage, adding: “We do everything possible and impossible but without timely supply it harms us.”Western leaders travelled to Kyiv on Saturday in a show of solidarity with Ukraine as the country marked the second anniversary of the war.
Earlier on Sunday, Russians in the UK opposed to Putin’s conflict protested outside their country’s embassy in London.
Organised by the Russian Democratic Society, the demonstration was against the “egregious violence, war crimes, and human rights violations” perpetrated by Moscow.
Rishi Sunak has called on the United States to continue providing “bolder” military support for Ukraine, following the second anniversary of Russia’s invasion.
Writing in The Sunday Times, the Prime Minister also said Ukraine’s allies should use money obtained through Russian sanctions and assets to fund Ukraine’s defence.
The UK has pledged to invest £245 million in producing artillery shells for Ukraine and £8.5 million in humanitarian funding as the conflict enters its third year.
US President Joe Biden has struggled to secure approval for further military aid, as Republicans in the US Congress have sought to block military aid to Ukraine as part of a partisan battle over immigration.
