Can I delete purchase line on PO if Item is not received ?

Hi,

I am using NAV 2013. I have a question about Purchase Order.

We have some POs which were not received and invoiced in full. 

For example:

PO No. 0001

Purchase Line

Item A          Ordered 100      Received 100      Invoiced 100

Item B          Ordered 20        Received 0           Invoiced 0

The vendor said they wouldn't ship Item B to us in the future. Can I delete Item B on PO? Is there any negative impact?