The UN Human Rights Council announced it will convene a special session on Thursday to address alleged worsening Russian violations in its war in Ukraine.
More than 50 countries on Monday backed Kyiv's request for an extraordinary meeting of the UN's top rights body to examine "the deteriorating human rights situation in Ukraine stemming from the Russian aggression".
Yevheniia Filipenko, Ukraine's ambassador to the UN in Geneva, said the move would send a signal to Russian President Vladimir Putin, as he insisted Russia's war in Ukraine was necessary to defend the "Motherland".
"Together, we are sending another strong message to Putin and his clique of war criminals: you are isolated as never before," Filipenko said in a video message on Twitter.
"We want to see the UN take practical steps to address Russia's violation of human rights in Ukraine and the war crimes which it commits daily against our people."
Russia invaded Ukraine on February 24, triggering a wave of international condemnation.
Russia was a member of the Human Rights Council until the UN General Assembly in New York voted on April 7 to suspend it from the body and from sitting in judgement of other nations' human rights records.
Russia then immediately withdrew from the council.
During an urgent debate on the invasion, the body voted on March 4 to trigger a commission of inquiry -- the highest-possible level of investigation -- into alleged Russian violations during the war.
Filipenko said Monday she wanted the inquiry to probe "Russia's crimes committed in Bucha and other liberated areas", referring to the town outside Kyiv that has become synonymous with allegations of Russian war crimes.
A team of AFP journalists saw 20 bodies on Yablunska Street in Bucha on April 2. The Russian army said the scene had been staged.
"This is also an opportunity for the international community to focus on the situation in Mariupol, as well as forced transfers of our population, and other violations and abuses against innocent Ukrainian civilians," Filipenko added.
"We will not rest until we ensure that those who commit these crimes are held to account."
The meeting will convene at 0800 GMT and be webcast live in the six official UN languages.
As an ordinary observer, following its withdrawal from membership of the council, Russia will have the right to interject, as will its handful of regular allies.
The support of 16 members of the council -- more than a third of the membership -- is required to convene a special session.
The call received the backing of members including Britain, France, Germany, Japan, Mexico, the Netherlands, Poland, South Korea, Ukraine and the United States.
Outside the council, observer states including Canada, Colombia, Italy, Moldova, New Zealand, Norway, Peru, Portugal, Spain, Sweden, Switzerland and Turkey supported the call.
Kyiv's mission in Geneva said the council "has to act in response to horrendous human rights abuses and war crimes committed by Russia in Ukraine".
The Human Rights Council holds three regular sessions a year, in March, June and September.
Thursday's session will only be the 34th extraordinary meeting of the UN's top rights body since its creation in 2006.
UN human rights chief Michelle Bachelet said in late March that Russia's widespread and indiscriminate attacks in Ukraine were of "immense concern", warning that they could amount to "war crimes".