During his video address to a meeting of the U.N. Security Council, Ukrainian President said yesterday that "accountability must be inevitable" for Russia as he accused Russian troops of committing "the most terrible war crimes" since the Second World War, Reuters said on April 5.

Zelenskiy reportedly showed a short video of burned, bloodied and mutilated bodies, including children, in Irpin, Dymerka, Mariupol and Bucha, where Ukraine accuses Russian troops of killing hundreds of civilians.

CNN says the Ukrainian leader then criticized the body, asking representatives point blank: "Where is the security that the Security Council needs to guarantee?  It is not there, though there is a Security Council.”

"It is obvious that the key institution of the world designed to combat aggression and ensure peace cannot work effectively,” Zelenskiy added.  

TASS says Russia's Ambassador to the United Vasily Nebenziya then told the Security Council that Russian troops are not targeting civilians, dismissing accusations of abuse as lies.  He said that while Bucha was under Russian control "not a single civilian suffered from any kind of violence."

Nebenzya reportedly urged Ukraine’s President Vladimir Zelenskiy to not let the West "fight to the last Ukrainian." 

"Do not let the West go ahead with its plans.  Make the correct decisions that your country needs, because the West is ready to fight in Ukraine to the last Ukrainian," Nebenzya said addressing Zelenskiy in person.  "Do make this decision now. You are well aware of the real situation on the frontlines.  Or it may be too late."

At least 1,480 civilians have been killed and at least 2,195 have been injured in Ukraine between the start of the Russian invasion on February 24 and April 4, a UN official said at the meeting, citing updated numbers from the Office of the High Commissioner for Human Rights (OHCHR), according to CNN.  The latest figures on the number of Ukrainian civilians in the conflict had reportedly "more than doubled" since the last briefing to the UNSC on March 17.

Russian Foreign Minister Sergei Lavrov said on Tuesday that the discovery of bodies in the Ukrainian town of Bucha was a "provocation" aimed at scuppering talks between Moscow and Kiev.

"A question arises: What purpose does this blatantly untruthful provocation serve?  We are led to believe it is to find a pretext to torpedo the ongoing negotiations," Lavrov said in a video message broadcast on Russian television.