Some 43,000 Ukrainian soldiers have been killed since Russia’s invasion began, Volodymyr Zelensky has said in a rare admission of the extent of the nation’s casualties.
In a post on social media, the Ukrainian president said 370,000 others had been injured, though this figure included soldiers who had been hurt more than once.
He also claimed that 198,000 Russian soldiers had been killed and a further 550,000 wounded.
The BBC has not been able to verify these claims.
Both Russia and Ukraine have often desisted from publishing casualty figures and are thought to underplay the true costs of the conflict.
A recent report from news agency Reuters, quoting an unnamed US intelligence source, said the war had cost Russia 315,000 dead and injured troops – almost 90% of the number it first deployed when the conflict began.
Meanwhile, a New York Times report from August, which quoted US officials, put Ukraine’s war dead at 70,000 with up to 120,000 wounded.
Before Sunday, the last time Zelensky had given an update on Ukraine’s casualty figures was in February, when he put Ukrainian deaths at 31,000.
The Ukrainian president is thought to have been compelled to make his latest admission after incoming US president Donald Trump posted on social media that 600,000 Russians had been killed or wounded, while the figure for Ukraine was 400,000. Trump did not state where these figures were from.
While estimates of the war dead and injured vary, the consensus is that Russian casualty figures are far higher than Ukraine’s due to their “meat grinder” tactics.
Recent developments in the war have only added to the number of dead.
Russian forces continue to make incremental advances along the eastern front line, capturing and retaking about 2,350 sq km of territory (907 sq miles) in eastern Ukraine and in Russia’s western Kursk region since the start of the year.
Ukrainian forces maintain control over a small amount of Russian territory after launching a surprise offensive into Russia in August.
The UK’s defence ministry says that in November, Russia suffered 45,680 casualties – more than during any month since its full-scale invasion began in February 2022.
According to the latest UK Defence Intelligence estimates, Russia is losing an average of 1,523 men killed and wounded a day.
On 28 November, it says, Russia lost more than 2,000 men in a single day, the first time this has happened.
These figures were based on open-source material, sometimes cross-referenced with classified data, officials said.
Ukraine does not allow its own military casualties to be published, so there are no official estimates covering the last few months.
The Russian defence ministry says more than 38,000 Ukrainian soldiers have been killed or wounded in Kursk alone – a number that cannot be verified.
Russia annexed the Crimean peninsula in 2014. Eight years later, it launched a full-scale invasion of Ukraine and has occupied territory in the country’s south and east.
Zelensky mentioned Ukraine’s war dead in a broader post about the prospects for an eventual end to the war.
It follows talks in Paris on Saturday with French President Emmanuel Macron and Trump. The US president-elect has said on numerous occasions that he wants a quick end to the war, playing on the sentiment held by around a quarter of Americans that the US is providing too much support to Ukraine.
During the campaign, Trump repeatedly said he could end the war between Russia and Ukraine “in a day” – but has yet to specify how he intends to do so.
In his post, Zelensky stressed that any peace deal had to be backed by effective international guarantees for his country’s security.
He said he told Macron and Trump that Kyiv needs an “enduring peace” that Moscow would not “destroy in a few years”.
