Jahanbakhsh's team had the opportunity to take all three points and finish second in Group B in the dying seconds of the game, but the chance was lost as Iran were booted out of the competition.
"It's such a big disappointment for us. We created some chances but unfortunately we didn't score," he told reporters.
"We had a big chance at the end of the game, we could have scored and won it. As everyone has seen, we did our best to win this game but we missed some chances."
Portugal and Spain qualified for the knockout rounds as Iran and Morocco's journey in Russia comes to an end.