You will file a 1120-F return US Tax return for a Foreign Corporation. you'll enter zeroes on all lines of the income tax form to show no sales were generated, no expenses incurred and no tax credits earned. Please download the form here to print and mail the form.
Because of some of the detail that is listed on the form, you may wish to enlist the services of CPA to fill this out and file for you just to make sure that the filing requirements are met.