Depends on what you are are asking.
A US federal registration is prima facie evidence of ownership and distinctiveness of the subject mark in the United States, its possessions and territories; provides constructive notice thereof; and entitles the owner to proceed in US federal court for infringement thereof.
If your question is "Can I be sued in a UK court on the basis of a US federal registration?" The answer, absent some contract enforcible in the UK, is no.
If your question is "Can I be sued in the US on the basis of a US federal registration, arising from activities conducted in the UK?" then the answer is going to depend on whether and how your UK activities affected US commerce - for example, are you attempting to export mislabeled goods into the US or otherwise making an effort to conduct commercial activity in the United States on the basis of your UK activities.
If your question is whether a US federal trademark filing can be used as a Paris or Madrid convention priority document in the UK trade marks office, the answer is it certainly can.
There are yet other ways of attempting to interpret your question, but it's not at all clear what you are trying to drive at.