From that clip, it's clear to me that he's British (which I knew) but that he has lived in the USA for a while and has picked up a slight North American twang. It's only audible on a few words. I wouldn't have been able to tell you where in the UK he was from just from listening to that. However, IMDB.com shows that he was born in Leeds. I have just watched as short clip of A Clockwork Orange and his Northern accent is much more audible in that. Over the years, I think he has lost it and, as I said, the slight American twang makes his original accent very difficult to pin down.