In the US and other countries banks do not take account of your credit status from your home country. Even an existing arrangement with an international credit card provider will not transfer when you move to the US. You will need to either use your employer to help you get around the problem or find banks with schemes for expats where the credit is supported in some way by your employer.
You simply need to obtain a credit card and use it once and your initial credit status is established. Once established there is generally no shortage of providers willing to offer a credit card.
If you want to make a more substantial use of credit, such as leasing a car or buying a house, you will need to find one of the specialist providers who deal with expats or find a bank with special deals for expats. For international assignees they will often find that their employers have arrangements with a bank that can help to secure the necessary credit. You should, however, make sure that the services offered meet your needs and that there are not more suitable deals available elsewhere