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 medium heat until thick, stirring constantly. Add the pineapple, meatballs and green pepper. , Simmer, uncovered, until heated through, about 20 minutes. Serve with rice.