The Council of the District of Columbia shall, prior to transferring to the Agency right, title, and interest in and to any of the said property described in § 6-321.01, determine whether such property is necessary to the redevelopment of the southwest section of the District of Columbia in accordance with a master plan approved by it, and, if it so finds, it shall, acting on behalf of the United States, transfer and donate to the Agency all right, title, and interest of the United States in and to so much of said property as it determines is necessary to carry out such master plan.