A small group of Ukrainian child survivors of war will address a private meeting at the UN in New York, timed to coincide with a meeting of the security council on Friday, as part of an effort by Kyiv to remind Americans of the human costs of a conflict increasingly affected by US domestic politics. Those due to address the event include Kira, 14, and Ilya, 11, from the besieged city of Mariupol, and the hope is that their personal stories will resonate with Republicans at a time when a military aid for Ukraine package is stalled in the House. “I was standing at a bus stop at 6am, waiting to go to school, when I started hearing a few explosions. It was then I realised the war had started,” Kira told the Guardian before her trip to New York, which will be followed by a visit to Washington. The loss of Kira’s childhood innocence was immediate. She spent about a month sheltering, hiding in houses, basements and at one point a church, as Mariupol was pounded and food, water and electricity were desperately short. At first she fled to her grandfather’s, then with her father, Yevhen Obedinskyi, to “a noisy district”, said Kira where “over about a week and a half, the explosions were heard more and more”. Eventually it reached the point where they felt they had to escape – only for disaster to strike. Yevhen was killed and, because “the Russians were shooting at the windows”, Kira and the family she was with had to leave his body behind, fleeing to hide in a cellar where they could endure a while longer. After a few desperate weeks, the girl, members of her father’s girlfriend’s family and some other families finally attempted to flee Mariupol. She remembers they were told they would be given chocolate if they got out of the city, but they were intercepted and captured by pro-Russian separatists instead. A five-year-old child in the group was seriously wounded in the capture. Kira remembers “a boom happened” and she eventually ended up in a hospital in occupied Donetsk, from where she says she was told by Russians she would be sent to an orphanage if her relatives from Ukraine could not cross the lines to get her. Yevhen’s father, Oleksander Oberdinskyi, got to hear of his granddaughter’s whereabouts and engaged in a two-month battle to bring her back to Ukraine, which involved him making the dangerous trip to Donetsk to successfully rescue her. Ukraine’s prosecutor general estimates that 528 children have been killed since the full-scale invasion began almost two years ago and 2,134 are missing. Another 19,500 are believed to have been abducted and taken to Russia, with some being forcibly re-educated with a “pro-Russia patriotic and military-related education”, a US report said. The international criminal court in The Hague issued arrest warrants for Vladimir Putin and Russia’s children’s rights commissioner, Maria Lvova-Belova, in March 2023, arguing there were grounds to suspect they bore responsibility for the “unlawful deportation” of thousands of children. One of the reasons for Kira’s visit to the US is to highlight the plight of the abducted, and she hopes supporters will sign a petition calling on the UN to demand that Russia repatriates them. “I want the children in a similar situation as mine, who were taken out of Russia, to come back to Ukraine to their families,” she said, sitting with her grandfather safely in the west of Ukraine. Another is more subtly political. The idea of sharing accounts such as Kira’s is to “raise awareness of Ukraine’s fight for democracy and freedom through human stories”, said Mariette Hummel, of Builders Ukraine, an NGO that is campaigning for the west to continue supporting Ukraine, and helped to organise the children’s visit, in which they will also visit a public school in Washington and appear on television. Advisers say the underlying recognition is that the debate about further military aid to Ukraine has become increasingly partisan. Ukraine’s president, Volodymyr Zelenskiy, has become notably less popular with Republican voters and politicians, a group of whom are blocking the foreign aid package from coming to a vote in the House. Eleven-year-old Ilya said he was eager to go the US to tell his story and what he had gone through. Like Kira, when the war started he and his mother shuttled from place to place across Mariupol in an increasingly desperate search for shelter – first at home, then in a hotel bunker, before trying to return home. But the family home had been destroyed. “I could not understand,” he said. “I’d lived in that home many years. I loved this house, and this horrible thing had happened. It was really scary.” They found a nearby home with two floors, some food and water inside, and they sought safety there. Catastrophically, it was a false hope. Heavy shelling continued and at one point shrapnel from an explosion flew towards mother and son, hitting him in the thighs and his mother, Natalia Matviienko, in the forehead. It turned out to be a fatal wound, and Ilya recounts, briefly and with extraordinary bravery, that his mother died the following morning with him. She was in his arms; at the time he was nine. Ilya was captured by Russian soldiers soon afterwards – he said one tried to give him a poisoned chocolate – and ended up in a Donetsk hospital. He was rescued by his grandmother Olena, though Ukrainian officials do not want to say exactly how, and she was able to bring him back on his 10th birthday. At first the trauma of what had happened hit Ilya hard. “At first he was afraid, very afraid, and he could not eat well because he went through the occupation,” Olena said, but he has improved considerably since. “Many people currently do not understand what actually has happened what’s going on right now in Ukraine, and Ilya is already talking very calmly about it,” she said. This article was amended on 23 February 2024. An earlier version said the children were addressing a meeting of the UN security council following information, which has now been amended, posted on the UNSC website.