As the last replier pointed, every state has different requirements for the CPA exam, but most of the states require an eligible candidate to complete 27 to 30 hours of (upper level) accounting courses, except for DE, CO and some other state. In addition, the candidate should meet 150 hours of business courses. In my opinion, the courses you took in Nepal might not get fully transfered out here because of the different accounting principles adopted by GAAP and FASB (Financial Accounting Standard Board). But you might want to contact your state CPA board to verify the information.

However, if the board allows you to sit for a CPA exam, as you mentioned, you would need to complete 1 or 2 years of auditing or public accounting experience under a licensed CPA in addition to completion of all 4 CPA exams, before you are designated with a CPA title. Like I said, your experience under a Chartered Accountant, may or may not qualify due to difference in accounting principles and practices in USA and Nepal. If I were you, I would contact the state CPA board for more information.