It also said 1,597 had been wounded since the beginning of Moscow's military operation that is on its seventh day, Russia's RIA news agency reported.
Russia's defence ministry disclosed on Wednesday that 498 Russian soldiers had died in Ukraine.
It also said 1,597 had been wounded since the beginning of Moscow's military operation that is on its seventh day, Russia's RIA news agency reported.
It was the first time that Russia had disclosed the number of casualties suffered in the war.
The ministry said over 2,870 Ukrainian soldiers and "nationalists" have been killed and about 3,700 wounded, according to Interfax.
Ukrainian authorities earlier said over 2,000 civilians had been killed in seven days since Russia launched the war.
This was disclosed by the State Emergency Service of Ukraine on Wednesday.
"Russia destroyed transportation infrastructure, houses, hospitals and kindergartens," the service said in a statement, according to AA. "During this time, more than 2,000 Ukrainians died, excluding our defenders."
It added that the service managed to save more than 150 people on Wednesday, put out more than 400 fires that broke out after enemy shelling, and evacuated more than 500 people. Pyrotechnicians also neutralised 416 explosive devices.
Ten rescuers were killed and 13 were injured in the process, the statement said.
The announcement came ahead of the expected second round of Russia-Ukraine peace talks. The first session was held on Monday.