Up to 13,000 Ukrainian soldiers have been killed since the start of Russia's invasion, a senior official has said.

Mykhailo Podolyak, an adviser to Ukrainian President Volodymyr Zelensky, said between 10,000 and 13,000 troops had died.

Neither Ukraine nor Russia tend to release figures for casualties, and Mr Podolyak's comments have not been confirmed by the Ukrainian military.

In June he said between 100 and 200 Ukrainian soldiers were dying daily.

Last month, the most senior US general, Mark Milley, said around 100,000 Russian and 100,000 Ukrainian soldiers had been killed or wounded since the start of the war.

In a video address on Wednesday, EU Commission head Ursula Von der Leyen said that 100,000 Ukrainian troops had been killed. However a spokesperson for the EU Commission later clarified that this was a mistake, and the figure referred to those both killed and injured.

Speaking to Ukrainian TV outlet Channel 24, Mr Podolyak said Kyiv was "openly talking about the number of the killed".

"We have official evaluations by the General Staff, official evaluations by the commander-in-chief [Mr Zelensky], and they range from 10,000 to 12,500-13,000 killed," he said.

He added that the number of civilians killed could be "significant". BBC News had identified about 3,600 civilian deaths as of mid-June. The figure is now likely to be much higher.

Ms von der Leyen said 20,000 Ukrainian civilians had been killed. While that number was not retracted by the EU Commission, it was removed from later versions of the video along with the assertion that 100,000 troops had been killed.

Mr Podolyak also suggested that up to 100,000 Russian soldiers had been killed since the invasion began on 24 February, and that a further 100,000 to 150,000 had been wounded, or were missing or unable to return to combat.

The BBC's Russian Service has established that at least 9,311 Russian soldiers of all ranks have been killed since the invasion on 24 February while the true death toll could be more than 18,600.

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