Iran defeated Serbia 3-1 in Belgrade at 2025 Volleyball Nations League in June.
Team Melli advanced to the next stage as runner-up and will meet Pool H top side Serbia, while Tunisia play Czech Republic.
Italy is the defending champion, having won its fourth title in 2022.
Taking place in Manila, Philippines, the championship features 32 teams from across the world competing for the coveted title, divided into eight pools of four teams, where the top two advance to the knockout stage.