It is indeed; in fact that is where I got mine done, but it took at good week for the fingerprint data to get from Farnborough to the TSA database.
So, whereas getting fingerprints (and everything else like the medical, the writtens, and perhaps all the FAA logbook flight time requirements
) done in the UK is a better form of risk management, it may be quicker to do the fingerprints in the USA in this case as that will cause a delay of perhaps only a couple of days.