The situation in the Ukrainian port city of Mariupol is "catastrophic," and the Ukrainian forces are largely to blame for it, a UK citizen identified as Aiden Aslin, who reportedly fought in the city, said in a video obtained by RT.

The British man apparently surrendered to Russian forces along with Ukrainian marines earlier this week.

Aslin said that when he joined the Ukrainian military in 2018, he believed he was with the "good side." He explained that the situation in Mariupol was "an eye-opener" for him, claiming he sought to convince his commanders to leave the city, but they chose to stay, not least because Kiev supposedly wanted them to stay.

"The situation in Mariupol is catastrophic. It could have been avoided should Ukraine have left but they chose to stay. Zelensky had a big role [in this decision]. He could have told them to leave but they stayed. I did not want this, I wanted to leave because we do not need war," Aslin can be seen saying in the video.

What he saw in the city during the weeks of heavy fighting also influenced his views on the Ukrainian military. "It was like seeing reality for the first time," Aslin said, adding that he witnessed a "lack of care for civilians" on the part of the Ukrainian military.

"They [the Ukrainian soldiers] looted supermarkets when civilians needed food to survive in the encircled city; they [the military] took food from the supermarkets. They would stop civilians [from] going out to get water. They would stop civilians from taking water from a supermarket that had been looted; water they had themselves taken."