It is quite natural for people who associate with others who have strong accents to pick up some of the pronunciations that they might hear. However, this is something that usually takes a very long time, and for some people, it never happens. When a child is exposed to a diversity of languages, he/she will have a greater ability to pick up the subtitles of the other languages, where it is more difficult for adults to do the same thing. For instance, people who all speak English from the various countries where it is used, and even from place to place in a country, often find themselves picking up some of the speech of the group that has a larger population. If an American went to England for a long time (years) he/she would have been exposed to the accent of the British, and it might not be unusual for him/her to use some of the language that is more popular in England. Actually, I believe Madonna has been criticized lately because she gave a couple of interviews and affected a slight British accent. The press was all over her, because they have access to her interviews years earlier, and she has a New York accent. Their comments were something to the effect that she was "pretending" to be something she was not! I guess she could have picked up some verbiage that is more British than American, after all, she has been remaking herself for 30 years!
From your screen name, and the way you phrase your question, I am guessing that you are a person from India/Pakistan, or somewhere similiar. The accents from the people who speak English there are really difficult to understand most of the time for us Americans. I have a hard time understanding the person who helps me with my computer problems. But that is a situation that with some practice can be greatly diminished. I have gone on too long for this question, but, regardless, yes, it is possible to gain a different accent, it just takes time.