Moscow has called for a special UN Security Council meeting Monday to address claims that Russian forces committed atrocities against Ukrainian civilians in Bucha, a town outside Kyiv.

"In the light of heinous provocation of Ukrainian radicals in #Bucha Russia requested a meeting of UN #SecurityCouncil on Monday April 4," Dmitry Polyanskiy, Russia's deputy ambassador to the United Nations, said Sunday on Twitter.

Ukraine and Western leaders have erupted in outrage over the discovery of mass graves and hundreds of dead people in Bucha, a small town northwest of Kyiv. Ukrainian President Volodymyr Zelensky directly blamed Moscow for the "killings" of civilians, AFP reported.

Russia denied the accusations and said Kyiv staged footage of the corpses.

A senior Washington official swiftly slammed Moscow's UN move and said it was designed to "feign outrage."

"Russia is drawing from the playbook it used for Crimea & Aleppo: forced to defend the indefensible (here, the Bucha atrocities), Russia is calling a @UN Security Council meeting so it can feign outrage & call for accountability," tweeted Samantha Power, a former US ambassador to the UN.

"Nobody is buying it," added Power, who is the current administrator of the US Agency for International Development.

UN authorities have yet to publicly state whether a Security Council emergency meeting will take place Monday.