It's true about accents and dialects. Even in UK they are very different. For example, for me it's difficult to understand when people from Scotland are talking - they dialect is really strange and very specific. Welsh people also have typical accent. In US, there are Afro-American English which is like totally different language.
My accent is typical Eastern European, and I have no idea how to get rid of it. Probably main problem that I just don't speak in English often and this is why it's difficult for me to improve my pronunciation.