Russia will later Monday present "documents" to the United Nations about the "real nature" of the events in Bucha near Kyiv, where it has been accused of mass killings.
Moscow has called for a UN Security Council meeting on what its deputy ambassador to the body called a "heinous provocation of Ukrainian radicals in Bucha."
On Sunday, Ukrainian prosecutor general Iryna Venediktova said 410 civilian bodies had been recovered in the wider Kyiv region after Russian troops pulled back.
In Bucha, the local mayor said 280 people were buried in mass graves because they could not be buried in cemeteries that were within firing range.
AFP on Saturday saw the bodies of at least 22 people in civilian clothes on a single street in Bucha.
"Today through our permanent representative (at the UN), we will organise a press conference in which precise documents will be presented on the real nature of events," Foreign Minister Sergei Lavrov said.
The press conference will be held at 1930 GMT in the UN headquarters in New York.
Russia has "categorically" denied any role in civilian killings in Bucha. Lavrov has spoken of fake images and a "disinformation" campaign.
Ukrainian President Volodymyr Zelensky accuses Russian troops of being behind the killings, saying: "These are war crimes and it will be recognised by the world as genocide."
US President Joe Biden called for a "war crimes trial" over the alleged atrocities in Bucha and said he would seek "more sanctions" against Moscow.
Russia began what it calls a military operation in Ukraine on February 24.
