Handling Tariff charges without it revaluing inventory

PeopleSoft Purchasing/Payables 9.2 Image 43

We are a procure 2 pay company where we purchase items from vendors and either resell or give away as promotion. We are going to start entering tariff charges either on the PO side when ordering or on the payables side when we get the invoice. We figured we would just add an additional line item. However, they do not want this to be part of the value of the item itself. Not sure how we can do this.