The cost of insurance for international students is higher than it is for US citizens. The cost disparity stems from the amount of risk an insurance company takes on when insuring someone from another country.
Typically, the risk is higher because information on international students' history is limited. However, some companies will take into consideration the student's driving record in their home country, which can be very helpful.
The information in this answer is general in nature and is not legal or insurance advice for your specific situation. Policy language varies carrier by carrier; your declarations page is the final word. If you're unsure, call your agent before you need to file.