Around 13,000 Ukrainian soldiers have lost their lives since Russia began its military operation in Ukraine on February 24, reported IANS citing a report.
According to BBC, Mykhailo Podolyak, an adviser to President Volodymyr Zelensky, on Thursday told Ukrainian media, "We have official evaluations by the General Staff, official evaluations by the commander-in-chief (Zelensky), and they range from 10,000 to 12,500-13,000 killed."
This comes after the head of the armed forces, in late August, said that nearly 9,000 troops had died.
He said that the number of civilians killed could also be "significant", reported IANS
“We are open in talking about the number of dead,” he said, saying more soldiers had been wounded than had died.
He added that up to 100,000 Russian soldiers were killed since the invasion began and that an additional 100,000 to 150,000 were wounded, or were missing or unable to return to combat.
Oleksiy Arestovych, another of Volodymyr Zelenskyy's advisers, claimed on Wednesday that the Russian death toll was around seven times that of Ukraine's.
There has been no confirmation by the Ukrainian military regarding the numbers claimed by Podolyak.
The figure has come forth at a time when General Mark Milley, Chairman of the US Joint Chiefs of Staff, said last month that around 100,000 Russian and 100,000 Ukrainian soldiers have been killed or injured till date, reported IANS.
However, Moscow's September update revealed that only 5,937 troops had been killed since the start of the war.
The American General had also noted that between 15 and 30 million refugees have been created since Russia launched its invasion.
The UN has recorded 7.8 million people as refugees from Ukraine across Europe, including Russia.
Earlier, Ukrainian President Volodymyr Zelensky claimed that about 10 million households across the country are without electricity as Russian strikes have hit critical power infrastructure.
(With Agency Inputs)