Drain pineapple, reserving juice. Set pineapple aside. Add water to juice if needed to measure 1 cup; pour into a large skillet. Add 1/3 cup water, vinegar, soy sauce, brown sugar and cornstarch; stir until smooth. Cook over meduium heat until thick, stirring constatanly. Add pineapple, meatballs and green pepper. Simmer, uncovered, for 20 minutes or until heated through.