Inventories are being kept tight in hope of increasing full-price selling and reducing markdowns.
The music star had launched the collection last February during New York Fashion Week.
The designer took the stage at an event at the Apple Store on Monday night.
Trade associations say high duties are an impediment to reform.
The designer will showcase her spring collection at the May 6 luncheon, which will benefit the Samuel Waxman Cancer Research Foundation.
The designer has created the costumes for “Le Palais de Cristal,” a ballet by George Balanchine first created in 1947, which is being reprised in May.