Most foreign nationals enter the US to work on a temporary basis as nonimmigrants. There are several visa categories available for employers when employing foreign nationals on a temporary basis.
If you intend to hire a foreign national on a permanent basis, this is done through sponsorship for US permanent residence—also known as a Green Card.
If you are a foreign company that has not yet established operations in the United States or need to send employees to an affiliated US office, there are several options to consider for expanding your company into the US.
Canadian citizens are able to enter the US without a visa as visa-exempt. This allows them to enter the US for acceptable business activities without the need for a visa. However, for durations from 90 days to 180 days, most foreign nationals will require a Visitor Visa to enter the United States.