Uskoković was a member and the team captain of the Serbian U-18 national basketball team that won the gold medal at the 2017 FIBA Europe Under-18 Championship. Over seven tournament games, he averaged 9.9 points, 3.1 rebounds, and 3.7 assists per game. Uskoković was a member of the Serbian under-20 team that finished 15th at the 2019 FIBA U20 European Championship in Tel Aviv, Israel. Over seven tournament games, he averaged 6.7 points, 5.3 rebounds, and 6.7 assists per game.