Villagers walk past unexploded artillery shells as they collect scrap metal from a bombed warehouse in the village of Malaya Rohan, Kharkiv region, Wednesday, May 18, 2022. (AP Photo/Bernat Armangue)

In this photo taken from video released by the Russian Defense Ministry on Wednesday, May 18, 2022, shows a wounded Ukrainian servicemen lying in a hospital in Novoazovsk, Ukraine, in territory under the government of the Donetsk People's Republic, after he an his comrades were evacuated from Azovstal steel plant in Mariupol. (Russian Defense Ministry Press Service via AP)

Russian army Sergeant Vadim Shishimarin, 21, is seen behind a glass during a court hearing in Kyiv, Ukraine, Wednesday, May 18, 2022. The Russian soldier has gone on trial in Ukraine for the killing of an unarmed civilian. The case that opened in Kyiv marked the first time a member of the Russian military has been prosecuted for a war crime since Russia invaded Ukraine 11 weeks ago. (AP Photo/Efrem Lukatsky)

A view of a street in Mariupol, in territory under the government of the Donetsk People's Republic, eastern Ukraine, Tuesday, May 17, 2022, with the Azovstal steel plant in the background. (AP Photo/Alexei Alexandrov)

Forensic experts inspect bodies of dead Russian soldiers during an identification process in Kharkiv, east Ukraine, Tuesday, May 17, 2022. (AP Photo/Bernat Armangue)

In this photo taken from video released by the Russian Defense Ministry Press Service on Wednesday, May 18, 2022, Ukrainian servicemen leave the besieged Azovstal steel plant in Mariupol, Ukraine. (Russian Defense Ministry Press Service via AP)

A cat walks past burned out cars in Mariupol, in territory under the government of the Donetsk People's Republic, eastern Ukraine, Tuesday, May 17, 2022. (AP Photo/Alexei Alexandrov)

In this photo taken from video released by the Russian Defense Ministry Press Service on Wednesday, May 18, 2022, Russian servicemen frisk Ukrainian servicemen after they leaved the besieged Azovstal steel plant in Mariupol, Ukraine.(Russian Defense Ministry Press Service via AP)

Employees of US embassy in Ukraine raise the US national flag at the US embassy, as Russia's attack on Ukraine continues, in Kyiv, Ukraine, Wednesday, May 18, 2022. (AP Photo/Efrem Lukatsky)

NATO Secretary-General Jens Stoltenberg displays documents as Sweden and Finland applied for membership in Brussels, Belgium, Wednesday May 18, 2022. NATO Secretary-General Jens Stoltenberg said that the military alliance stands ready to seize a historic moment and move quickly on allowing Finland and Sweden to join its ranks, after the two countries submitted their membership requests. (Johanna Geron, Pool via AP)

Buses with Ukrainian servicemen evacuated from the besieged Mariupol's Azovstal steel plant travel accompany Russian APC's to a prison in Olyonivka, territory under the government of the Donetsk People's Republic, eastern Ukraine, Tuesday, May 17, 2022. More than 260 fighters, some severely wounded, were pulled from a steel plant on Monday that is the last redoubt of Ukrainian fighters in the city and transported to two towns controlled by separatists, officials on both sides said. (AP Photo/Alexei Alexandrov)

In this photo taken from video released by the Russian Defense Ministry Press Service on Wednesday, May 18, 2022, Russian servicemen watch Ukrainian servicemen boarding a bus after they leaved the besieged Azovstal steel plant in Mariupol, Ukraine.(Russian Defense Ministry Press Service via AP)