FILE - Tetiana Poltorak, left, and Tetiana Artemenko place flags to honor Ukrainian prisoners of war killed in the Olenivka region at a memorial site near the Independence Square in Kyiv, Ukraine, Wednesday, July 5, 2023. (AP Photo/Jae C. Hong, File)
People attend a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia, at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)
People attend a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia, at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)
Soldiers of Ukraine's Azov battalion pray at a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia, at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)
A young woman in folk headgear attends a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia, at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)
Soldiers of Ukraine's Azov battalion light flares at a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia, at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)
Soldiers of Ukraine's Azov battalion light flares at a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)
People sing the national anthem at a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia, at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)
Activists hold posters and shout slogans at a rally demanding to free Ukrainian prisoners of war who are held in captivity in Russia, at Independence Square in Kyiv, Ukraine, Sunday, July 28, 2024. Several thousand people and soldiers gathered to commemorate the second anniversary of a Russia-orchestrated explosion that killed more than 50 Ukrainian prisoners of war in the Russian-held Olenivka prison barracks. (AP Photo/Efrem Lukatsky)