Entering the United States on a temporary basis generally requires one to first obtain an appropriate visa. A U.S. visit that is temporary and for pleasure, for business (NOT employment), or for medical treatment typically require a visitor visa
While it does not permit gainful employment while in the U.S., the B-1 for business is appropriate for certain activities related to commercial transactions. This visa category is used for personal and/or domestic attendants of certain nonimmigrants and U.S. citizens.
The B-2 category is intended for tourism, social visits, certain medical treatments, and participation in amateur sports, music, and similar events. This category is also used for domestic partners not in a marital relationship, to accompany their qualifying partners.