Live updates: follow the latest news on Russia-Ukraine
Ukrainian President Volodymyr Zelenskyy on Tuesday offered macabre details of alleged Russian atrocities in his war-torn country and said the UN system was not fit for dealing with Moscow’s aggression.
Wearing khaki fatigues and sitting in front of a Ukrainian flag, Mr Zelenskyy recounted evidence of murder and torture of civilians by Russian forces in recently liberated parts of northern Ukraine and likely elsewhere in his war-torn country.
“They killed entire families, adults and children, and they try to burn the bodies,” Mr Zelenskyy said via a video-link, in his landmark first address to the UN Security Council.
“Civilians were crushed by tanks while sitting in their cars in the middle of the road. And just for their pleasure, they cut off limbs ... slashed their throats."
He said women and been raped and murdered, sometimes in front of their children, and added gruesome details about victims' tongues being pulled out.
Mr Zelenskyy said the masterminds of Russia’s invasion of Ukraine should face a Nuremberg-style war crimes tribunal and called for a reboot to a global security system that has struggled to answer Moscow’s aggression.
The veto power enjoyed by Russia and the UN Security Council's other four permanent members — Britain, China, France and the US — left the body powerless when one of those five powers breaks international norms, said Mr Zelenskyy.
"Do you think that the time of international law is gone? If your answer is no, then you need to act immediately," he told the chamber.
"The UN system must be reformed immediately so that the veto is not the right to die."
Mr Zelenskyy’s video address comes after discoveries of evidence that Russian forces killed unarmed civilians as they withdrew from around the capital, Kyiv, and from the nearby city of Bucha.
"The massacre in our city of Bucha is unfortunately only one of many examples of what the occupiers have been doing on our land for the past 41 days,” he told diplomats in New York.
"Russian troops are deliberately destroying Ukrainian cities to ashes with artillery and air strikes. They are deliberately blocking cities, creating mass starvation. They deliberately shoot columns of civilians on the road trying to escape from the hostilities."
Moscow has denied attacking civilians in a military operation that it said is necessary to prevent the eastward expansion of the Nato military alliance.
Russia’s UN ambassador Vasily Nebenzya said the images from Bucha were a "horrific provocation", staged by Ukrainian forces. He also described armed Ukrainian nationalists committing abuses against civilians and accused western nations of using Ukraine as a "pawn" in a bid to isolate Moscow.
Mr Zelenskyy accused Russian President Vladimir Putin of genocide in Ukraine since the February 24 invasion and said that more of Moscow’s “atrocities” would come to light as it repositions its forces to the south-east.
Diplomats later watched a video of shocking images of what appeared to be executed civilians and half-torched corpses from various cities across Ukraine.
Mr Zelenskyy's first address to the UN chamber follows video appearances for the US Congress and parliaments around the world. Russian and Chinese diplomats were present in New York.
The president visited Bucha on Monday to see evidence of a mass grave and the bodies of people who were bound and shot. Flanked by soldiers, Mr Zelenskyy, wearing a flak jacket, appeared emotional.
Barbara Woodward, the UN ambassador for Britain, which holds the council’s rotating presidency for the month of April, said images from Bucha were “harrowing, appalling, probable evidence of war crimes and possibly a genocide”.
Still, no formal council action was expected on Tuesday, given Russia’s UN Security Council veto power.
UN Secretary General Antonio Guterres lamented the “horrifying images of civilians killed in Bucha” and the “personal testimony of rapes and sexual violence that are now emerging”.
He called for an independent investigation so those responsible face justice.
The UN’s top humanitarian Martin Griffiths met Russian foreign minister Sergei Lavrov and defence chiefs in Moscow on Monday and will soon head to Ukraine in a bid to broker “military freezes” to rescue civilians from bombed-out cities.
Russian officials promised to study his suggestions for humanitarian access, Mr Griffiths told diplomats, but added that he “came away from these meetings believing that we have a long road ahead of us”.
Washington's UN envoy Linda Thomas-Greenfield highlighted reports of Russian forces forcing tens of thousands of Ukrainian civilians from Mariupol and other besieged cities and relocating them to Russia.
She told the UN Security Council of “credible reports” that “children are being abducted – along with mayors, doctors, religious leaders, journalists, and all who dare defy Russia’s aggression” and taken to “so-called filtration camps” and packed off to Russia.
“Reports indicate that Russian Federal Security agents are confiscating passports and IDs, taking away cellphones, and separating families from one another,” she said.
“I do not need to spell out what these so-called filtration camps are reminiscent of," she said, in an apparent reference to Nazi concentration camps during World War Two.
"It is chilling. We cannot look away.”
Britain and the US are intensifying their pressure on Russia, pushing for its removal from the UN’s Geneva-based Human Rights Council. A vote on suspension of Russia in the 193-nation General Assembly could happen this week.
The General Assembly has twice voted to censure Russia for its aggression in Ukraine.
The roughly 140 votes against Russia in those two polls exceeded the two-thirds threshold needed for suspension, but it remains unclear whether UN members would back the more drastic step of ejecting Moscow from the human rights council.
Ms Thomas-Greenfield said Russia’s presence on the rights council “undermines the entire UN” and “is just plain wrong”. Governments should “come together to do what is right”, she added.