Kilmarnock Willow frost damage

I have a young tree planted 1 year ago (about 3 ft.tall) I think it sustained some frost damage over the winter, and is now sprouting leaves only from the bottom half. The top branches aren't real brittle, but also have no leaves (The lower ones came out over a month ago) I am wondering if I should prune it at this point, or just leave it alone and hope it recovers ) I bought this tree from a nursery last year, and unfortunately they went out of business so I can't ask them........ Any advice would be helpful.....thanks!