A still from a video purportedly showing the Ukrainian prisoner of war before he was killed.
After graphic footage of an unarmed Ukrainian prisoner of war surfaced online, Ukraine vowed to track down the Russian soldiers responsible.
“We will find the murderers,” said President Volodymyr Zelensky late Monday.
The Ukrainian soldier is seen in the video smoking a cigarette in a trench. He declares “glory to Ukraine” before being shot with automatic weapons.
The Ukrainian military identified him on Tuesday as Tymofiy Shadura, who had been missing since 3 February.
According to the 30th Separate Mechanised Brigade, he was last seen near the eastern city of Bakhmut, which has seen heavy fighting in recent months.
“Our serviceman’s body is currently in temporarily occupied territory,” the statement said, citing preliminary information. It went on to say that once the body was returned, the identification could be completed.
Separately, Ukraine’s armed forces’ general staff stated: “The shooting of an unarmed prisoner is a callous and brazen disregard for international humanitarian law and war customs. Not warriors, but worthless murderers, do this.
“The Russian occupiers have once again demonstrated that the brutal extermination of Ukrainians is their main goal in Ukraine.”
Mr Shadura’s sister told the BBC before the soldier was named: “My brother is certainly capable of confronting the Russians in this manner.
“He had never hidden the truth in his life and would never do so in front of the enemy.”
After the prisoner of war (POW) is shot dead, one of the shooters, believed to be a Russian soldier, is heard saying “die” and using an expletive.
The alleged murderer or murderers, who are not seen in the video, have not been identified.
The BBC has not confirmed where or when the footage was shot. On Monday, it first surfaced on social media.
Since President Vladimir Putin launched a full-scale invasion of Ukraine on February 24, 2022, Kiev and its Western allies have accused Russian troops of committing mass war crimes. The allegations are denied by Russia.
An execution-style killing on a Bucharest street
President Zelensky said in his video address that “the occupiers” killed “a warrior who bravely said to their faces: ‘Glory to Ukraine!'”
“I want us all to respond to his words as one: ‘Glory to the Hero! All hail the Heroes! Ukraine, bravo!'”
Mr Zelensky was referring to a military battle cry that has become popular among millions of Ukrainians.
Meanwhile, Ukrainian Foreign Minister Dmytro Kuleba said the footage was “yet another proof that this war is genocidal,” and he called for a “immediate investigation” by the International Criminal Court.
Dmytro Lubinets, Ukraine’s human rights ombudsman, accused Russian troops of committing war crimes by violating the Geneva Conventions on the treatment of prisoners of war.
Andriy Kostin, Ukraine’s Prosecutor General, said a criminal investigation had already been launched.
Ukrainian troops have previously been accused of torturing, raping, and killing Ukrainian prisoners of war.
In July of last year, a video surfaced showing a captured Ukrainian soldier being castrated in the Russian-occupied Donbas region of eastern Ukraine.
The Russian soldier filmed carrying out the attack in Severodonetsk was identified as a member of Chechen leader Ramzan Kadyrov’s unit.
Moscow accused Ukrainian forces of executing a group of Russian prisoners in November.
It came after a video from the front lines in eastern Ukraine showed a number of soldiers appearing to surrender in an incident that resulted in their deaths.
According to a Ukrainian official, the surrender was “staged” by Russian troops in order to attack their captors.