A Ukrainian serviceman sets up an anti-materiel rifle at a position, as Russia's attack on Ukraine continues, in the town of Marinka, in Donetsk region, Ukraine May 28, 2022. REUTERS/Anna Kudriavtseva 

An evacuation convoy travels from Russian troop-occupied Kupiansk town, along a damaged road, amid Russia's attack on Ukraine, on the outskirts of Kharkiv, Ukraine May 30, 2022. Picture taken May 30, 2022. REUTERS/Ivan Alvarado TPX IMAGES OF THE DAY 

A Ukrainian serviceman inspects a shell of a multiple rocket launch system, as Russia's attack on Ukraine continues, in the town of Marinka, in Donetsk region, Ukraine May 28, 2022. REUTERS/Anna Kudriavtseva 

An Ukrainian service member looks on as he rides on top of a military vehicle, amid Russia's invasion of Ukraine, on the road from Bakhmut to Kostyantynivka, in the Donetsk region, Ukraine, May 29, 2022 REUTERS/Carlos Barria 

A Ukrainian serviceman walks as seeds burn in a grain silos after it was shelled repeatedly, amid Russia's invasion of Ukraine, in Donetsk region, Ukraine May 31, 2022. REUTERS/Serhii Nuzhnenko 

A Ukrainian servicewoman Nataliia looks out of a trench at a position near a frontline, as Russia's attack on Ukraine continues, in Donetsk Region, Ukraine May 29, 2022. REUTERS/Serhii Nuzhnenko 

Old used cartridges are seen at a position of Ukrainian servicemen near a frontline, as Russia's attack on Ukraine continues, in Donetsk Region, Ukraine May 29, 2022. REUTERS/Serhii Nuzhnenko 

A view shows a residential building destroyed by Russian military strike, as Russia's attack on Ukraine continues, in the town of Bakhmut, in Donetsk Region, Ukraine May 29, 2022. REUTERS/Serhii Nuzhnenko 

Service members of pro-Russian troops drive an armoured vehicle along a street past a destroyed residential building during Ukraine-Russia conflict in the town of Popasna in the Luhansk Region, Ukraine May 26, 2022. The writing on the vehicle reads: "Valkyrie". REUTERS/Alexander Ermochenko 

Service members of pro-Russian troops play table tennis during Ukraine-Russia conflict in the town of Popasna in the Luhansk Region, Ukraine May 26, 2022. REUTERS/Alexander Ermochenko 

A police officer checks documents during an evacuation of local residents between shelling, amid Russia's attack on Ukraine, in the village of Novomykhailivka, in Donetsk region, Ukraine May 29, 2022. Picture taken May 29, 2022. REUTERS/Anna Kudriavtseva 

Ukrainian service members ride on top of a military vehicle, amid Russia's invasion of Ukraine, on the road between Kostiantynivka and Bakhmut, in the Donetsk region, Ukraine May 28, 2022. REUTERS/Carlos Barria 

Ukrainian service members ride on top of a military vehicle, amid Russia's invasion of Ukraine, on the road between Kostiantynivka and Bakhmut, in the Donetsk region, Ukraine May 28, 2022. REUTERS/Carlos Barria 

A service member of pro-Russian troops takes a rest during Ukraine-Russia conflict in the town of Popasna in the Luhansk Region, Ukraine May 26, 2022. REUTERS/Alexander Ermochenko 

Vladimir Mihailovich, a solar plant manager, walks inside a crater after a shelling hit the station that was producing 2.5 megawatts of power, amid Russia's attack on Ukraine, in the town of Merefa on the outskirts of Kharkiv, Ukraine May 28, 2022. Picture taken with a drone. REUTERS/Ivan Alvarado 

A police officer hides from a shelling as he checks a school during an evacuation of local residents between shelling, amid Russia's attack on Ukraine, in the town of Marinka, in Donetsk region, Ukraine May 31, 2022. Picture taken May 31, 2022. REUTERS/Anna Kudriavtseva TPX IMAGES OF THE DAY 

A Ukrainian serviceman walks in a trench at a position near a frontline, as Russia's attack on Ukraine continues, in Donetsk Region, Ukraine May 29, 2022. REUTERS/Serhii Nuzhnenko 

Plants grow in front of a residential building heavily damaged during Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine May 30, 2022. REUTERS/Alexander Ermochenko 

A Ukrainian serviceman shelters during a shelling, as Russia's invasion on Ukraine continues, near a frontline in Donetsk Region, Ukraine May 28, 2022. REUTERS/Serhii Nuzhnenko 

A Ukrainian serviceman inspects an area from a building damaged by a Russian military strike, as Russia's attack on Ukraine continues, in the town of Marinka, in Donetsk region, Ukraine May 28, 2022. REUTERS/Anna Kudriavtseva 

A Ukrainian serviceman is seen in a shelter at a position near a frontline, as Russia's attack on Ukraine continues, in Donetsk Region, Ukraine May 31, 2022. REUTERS/Serhii Nuzhnenko 

Tanks of pro-Russian troops drive along a street during Ukraine-Russia conflict in the town of Popasna in the Luhansk Region, Ukraine May 26, 2022. REUTERS/Alexander Ermochenko 

A rescuer inspects a flat where the bodies of civilians were collected, in a shelled residential building, as Russia's attack on Ukraine continues, in Kharkiv, Ukraine May 31, 2022. REUTERS/Ivan Alvarado