As of the 2016 season he is a member of the Sweden U19 team. He scored his first international goal in a friendly against Slovakia U19 in September 2015. The game finished 2-2 with Jajic opening the score tally. Jajić captained his country during the 2017 UEFA European Under-19 Championship, where Sweden finished last in its group following two losses in even games against Czech Republic and Georgia, and a surprising 2–2 draw against Portugal.