It will depend on what type of nonimmigrant visa you have. Only visas like H Visas with authorization to work in the U.S. can work while preparing for your E-2 Visa. However, if the work you are doing does not include remuneration, such as planning to purchase a business or setting up your business for your E-2 Visa, then it is allowed. Always ask your immigration lawyer about what you can and cannot do when you are applying for your E-2 Visa.
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