Today there are many varieties of English spoken around the globe. For centuries, British English was revered as the "most proper," or "correct" version of the English language. However, as the world has gained more exposure to different types of English and American English in particular, British English is not necessarily considered to be the best form of the language today.
American English proves to be gaining enormous popularity worldwide; in fact, many countries have adopted American English as the standard wherever English is taught in schools. Also, many non-U.S. students express greater desire to learn American English over other varieties.
When studying in the United States, an international student must keep in mind that variations do exist between varieties of English, and not just with regard to accent. Students who come to the United States with a background in British, Australian or other forms of English will notice the differences in language but will rarely encounter any serious communication problems. Even within the United States itself, a student will encounter different American English accents and dialects.
Even if your primary goal is to complete a degree in the United States and you do not plan to enroll in short term English training, you will be able to find help with language learning if you need it. Most universities offer intensive English classes for students who need extra preparation before they begin their degree. In addition, most universities can also provide special services or tutoring for non-native speakers of English.
In short, if students studying in the United States wish to integrate into and better understand American life and culture, they will find speaking American English to be an advantage. However, if you are someone who has learned British, Australian or other forms of English, you should not be worried. There are small differences between the variations and that will certainly not prevent you from having a successful collegiate performance.